Building Behemoth Part 3: Hops

In the last part of this series, I explicitly stated my opinion that there is no place for a big hop presence in an Imperial Stout, citing Pipeworks’ Close Encounters as an example of a stout that was just too hoppy for me. A good beer, without a doubt, but in my mind it is way closer to a specialty beer than a RIS, solely because of the hops.

This is my personal opinion showing, and even the 2015 BJCP Style Guidelines say that the hop flavor and aroma in an Imperial Stout can be high. I suggest trying a few examples and seeing what works for you!

In this part of the series, we are going to take a look at the hops and hopping techniques used by the professional and award-winning brewers. We’re also going to examine the data from the Reddit RIS survey a bit more in-depth and take a look at some other professional sources.

We Need Hops

Before my previous statements get taken as “don’t use a lot of hops in a RIS”, let me say that we definitely need hops in an Imperial Stout. A lot of hops, relatively speaking. They provide the bitter balance to the Imperial Stout’s sweetness, and with such a high OG it takes a lot of hops to provide said balance.

In an article (pointed out to me by /u/chino_brews of the /r/homebrewing community) by Kate Bernot of Draft, Founders Brewmaster Jeremy Kosmicki says:

I like our Imperial Stout a lot, and it gets a little underappreciated in our portfolio with Breakfast Stout and KBS in there, but I find so many imperial stouts that are just out of balance. Either there’s way too much cloying sweetness or way too much burnt flavor or they’re over hopped. The key to ours, and it goes in line with my philosophy of brewing in general, is balance. It’s about getting all those extreme flavors in there but balancing them.

Similarly, Eric Asebrook of Thirsty Dog says that the concept of an imperial stout is “balanced complexity”.

I couldn’t agree more with both of those statements, and they call out the necessity for balance, which the hops help provide. But how do you know how many hops to use?

Personally, I’m a big believer in IBU:OG ratios. They aren’t a hard and fast rule, but for a new recipe they are a great place to start. Taking a page out of Designing Great Beers by Ray Daniels, the average IBU/OG ratio for an Imperial Stout is .9. So, for example, let’s start with an Imperial Stout that has an OG of 1.100.

X (IBUs) / 100 (digits after the decimal) = .9

X = 90

So, in theory, a balanced Imperial Stout with an OG of 1.100 would need 90 IBUs. The point here is that we need hops, but in my opinion they should be balanced with the rest of the beer.

Professional and Award-Winning Recipes

The usual quick disclaimer, I hand-picked these examples because they are beers that I personally enjoy. That means any information here applies to my palate, and the beer I want to brew. If you like hop-forward aggressive stouts, you can easily do this research with examples you enjoy! Here is the hop schedule for each of the professional recipes that we utilized in the last part of the series.

ibuog

And here are the numbers from past NHC winning recipes, with the exception of 2013, which utilized homegrown hops and we can’t really know how many Alpha Acids are in the hops (we could ball park it, but who really knows).

nhchomechart

I find this information super interesting, and as usual the homebrewers don’t disappoint. Before we continue though, I want to point out that for ALL of these recipes, Alpha Acids are an approximation, and so these ratios almost certainly vary from their real life examples at least a little.

The first thing that stands out to me is that each of the commercial examples has an IBU/OG ratio of either .9 or .8. So that necessity for balance is reinforced in these examples. I’m actually surprised by the lower ratio in Yeti, which I’ve usually found to be a bit more hop forward than something like Ten Fidy, but that may just be evidence that 30 minute and late additions help reinforce the hop profile.

The homebrewers, on the other hand, are all over the board with a range from .45 – 1.28. Looking at this data, I feel into a trap, let fly an arrow, and then painted a really nice target around it. I wanted to say “Well, it looks like most of these are around .8” but really there is just too much variance here. It’s a beautiful thing, people are making great beer in a lot of different ways, and I love seeing the versatility that homebrewers have brought to the style.

Hop Timing

So when should we add our hops? And how many times should we add them? More often than not, I hear people advocate for two to three hop additions in a RIS, which is supported in the Reddit RIS Survey. The rationale is that most of these beers are going to improve with age, and with that aging perceived bitterness will decrease and hop aroma/flavor will rapidly fade. So you want a solid bitterness without worrying about the hop character.

With that in mind, what we have above is a really interesting set of data. We have an average of 3 hop-time additions. Meaning, no matter how many hops are used, they are typically being added an average of 3 times. The chart below shows how often each addition was used, and the average IBU of said addition.

numberibuchart

If we are purely going off data, it looks like the “average” RIS would have a 60, 30, and 0 minute hop addition with 85 total calculated IBUs. These numbers are pretty interesting, but I want to emphasize again that like grains, hops additions are relevant within the context of their recipe. Meaning a 60, 30, and 0 minute hop schedule looks like a solid rule of thumb, but that doesn’t mean it is “better” somehow that the 75, 45, 30, 15, 5, 0 schedule.

Hop Selection

We have an average of 2.75 different varieties of hops used per recipe. Typically the 60 minute addition is a different hop than the rest of the additions, which tend to be similar (or the same). The chart below shows the most used hops, and when they are typically used. Number of uses is out of 42, the total number of individual hop additions in every recipe.

hopvarietychart

I think this information is interesting, but it doesn’t mean much in isolation. Each of these hops were used with others, and there isn’t much consistency from recipe to recipe. Certainly nothing as clear as Chocolate/Roasted Barley grain split from the previous article. If you’re struggling with a RIS recipe, a good way to utilize this information would be to decide what sort of character you’re going for, deciding on a hop schedule, and then saying “Well, a lot of people used Centennial for bittering and the hop description is in line with what I want”. Always plan in the context of what you’re looking for, start with the product and work backwards. This chart is used to fill in those gaps.

As far as my own personal hop selection goes, I love Magnum or Challenger for bittering and Fuggles for Flavor/Aroma. If anything, this data shows us that there is a lot of variance in hop selection so do whatever works for your system and recipe!

My Hop Schedule

Going with the “start with a product” model, I don’t like aggressive hop character. I think a great RIS needs to be balanced, with some low supporting hop flavor. Aroma isn’t important to me, and I plan on aging this beer, so any aroma would be diminished anyways. There is certainly an argument for adding aroma hops so that, even in incredibly small amounts, there is a layer to add complexity to aroma that helps bring out the malt profile. I’m in full support of this, and I definitely want to experiment with it, but it just isn’t for me.

Here’s my hop schedule, aiming for an OG of 1.100 and an IBU/OG ratio of .9:

Magnum @ 60 60 IBUs
Fuggles @ 25 30 IBUs

 

Future Experiments

Really, there isn’t too much experimentation that I’m seeing here. I’ll openly admit I’m less concerned about the ways hops play a role, which is a limitation in my brewing. Bitter the beer for balance, a little flavor, and I’m happy.

That said, I do have some plans:

  1. Is there a difference between a beer with a 0 minute addition RIS and a RIS without a 0 minute addition fresh? After 3 months? 6? And which do I prefer?
  2. Is there a difference in a beer bittered with Magnum versus Challenger?
  3. Which IBU/OG ratio do I prefer?

The next part of this series will focus on yeast and yeast selection! I will also cover fermentation in this section, since the two are so related, and then I’ll reference back to fermentation in later articles.

Cheers!

Resources

Reddit Homebrewing, for their awesome survey participation

Bernot, Kate. “What makes a great imperial stout…and where can we find one?”. Draft. Jan 22, 2016. Retrieved from: http://draftmag.com/what-makes-a-great-imperial-stout/

BYO Staff. “Russian Imperial Stout: Tips from the Pros”. Brew Your Own. Dec., 2005. Retrieved from: http://byo.com/bock/item/1337-russian-imperial-stout-tips-from-the-pros

Daniels, Ray. Designing Great Beer.

American Homebrewers Association – Recipes

Past Parts of the Series

Part One: The RIS Survey

Part Two: Grain Bills

Building Behemoth Part 2: A Look at Imperial Stout Grain Bills

An Imperial Stout is, more often than not, defined by its grain bill. It isn’t a “hoppy” beer (though I have had some solid hoppy-RIS, like Close Encounters by Pipeworks), it isn’t required to have a specific yeast character, and while adjuncts like coffee often play a role, it typically isn’t considered a special subcategory of the style (though, if you’re submitting to a competition, consider the specialty category if the character is obvious).

In the last part of the series, we examined survey data from /r/homebrewing regarding their imperial stouts. In this part of the series, we are going to examine some of that data compared to data from other award-winning homebrewers and professional brewers.

Professional Grain Bills

When I build a new recipe, I like to start by examining clone data. Not a singular clone recipe, but looking at a whole bunch of recipes to see if there are similarities between them. Below are a few of my favorite imperial stouts on the market. If you’re a RIS fan and haven’t had some of these, I highly recommend trying them!

prostout

There is one piece of information I find incredible from this chart: every single one of them splits their roasted grain. Interesting, right? Not one of these stouts only uses Chocolate malt or Roasted Barley. Also interesting that they almost all use a Chocolate/Roasted Barley combo (there are a lot of other famous Imperial Stouts that fall under that umbrella as well, including Firestone Walkers’ Parabola) with Chocolate either leading the way or meeting the level of Roasted Barley.

Also interesting is the use of 2-Row rather than Maris Otter, except for Old Rasputin. This is something I’m skeptical of, if only because I’m not sure what sort of 2-row they are using. It could very well be Maris Otter, or it could be Briess 2-Row for all I know.

Another common addition? Crystal malts, specifically dark ones. Flaked Oats/Barley is also common.

Just as interesting is the amount of malts that don’t overlap! Quick list for reference:

  • Amber DME
  • Black Patent
  • Black Barley
  • Brown Malt
  • Caramalt
  • Carastan
  • Crystal 160L
  • Crystal 80L
  • Dark Crystal
  • Debittered Black Malt
  • Maris Otter
  • Munich
  • Flaked Wheat
  • Flaked Rye

That’s quite the list, and it shows that while there are certainly some similar trends among these grain bills, there is a lot of room for interpretation and experimentation in the style.

Award Winning Homebrew Grain Bills

I’m not a professional brewer, and I like to see how homebrewers are doing things as well. It’s entirely possible that in the scale of the process, there are differences in the grain bill as well.

nhcstout

The AHA was kind enough to let me get into the grain bills for past NHC winners. These are the RIS recipes that won gold! On the AHA site, NHC records go back to 2003, meaning we have had a total of 13 National Homebrew Competitions, and a RIS has won gold in its category 7 times, over 50%. Big percentage for that category.

So what does it look like homebrewers are doing? More of them are using Maris Otter than professional brewers, but quite a few are still using 2-row. And, like professional brewers, all but one of the NHC winners are splitting their roasted grain, AND like the professional brewers it is almost always a split between Chocolate/Roasted Barley.

Comparatively there is also way less crystal being used by the homebrewers.

Base Malts

It looks like there is a tendency to choose either Standard 2-Row or Maris Otter as the base malt for imperial stouts. Almost all of the recipes I see include one or the other, rarely a blend of both. On a professional scale, I was curious why so many breweries were using 2-row if Maris Otter was a “better” base malt. I guessed because it was cheaper. Yes, I legitimately thought this about stouts going into this, and I’ll own up to that.

I sent some emails, and the only brewery that got back to me was the incredible Oskar Blues, the email was written by their head brewer Tim Matthews. Tim’s excellent answer was to clear up the idea that the brewery may use 2-Row for a “commercial” reason (which they don’t). The breweries Pale Ale malt is purchased in bulk, it is incorporated into a lot of their recipes, but they use other base malts for some of their other beers when necessary. Pinner is an example of this.

The reason Tim gives for why they use 2-row reflects some of the answers we see from homebrewers. Looking back at the RIS survey, 60 people responded that they use 2-row as their base malt, while only 20 people said that they use Maris Otter. This seems to be consistent with the professional grain bills as well. Reasons for utilizing 2-row included that 2-row has a higher diastatic power and the bulk of the flavor for a RIS is from the Crystal and Roast malts. 2-row is the canvas, specialties are the paint.

So, looking at my own recipe, this really opens up 2-row as a possibility when I hadn’t considered it such before. Am I making sure there is enough diastatic power in my mash? Do I prefer the same grain bill with 2-row versus Maris Otter, or is it an apples and oranges argument? I’m adding it to the list of things I’d like to try, and getting a solid base malt is a vital step to making better beer.

On that note however, Tim’s comment also makes me think about the maltster for the base malt. In the first part of the series, I said that I was convinced one of the issues with my RIS was the use of Briess roasted malts. The survey didn’t necessarily support this, since a majority of users didn’t pay attention to the malster they used for their roasted grains. I’m still in favor of maltster making a difference, and if it matters in the grains that make up a small portion of the total grist, then I’d also assume it matters in the grain that makes up a majority. Is there a difference in a RIS made with Briess 2-row versus Rahr? Absolutely something to add to the list.

Roasted Malts

On the argument of maltster, Tim Matthews mentioned in a Reddit AMA that Oskar Blues uses all Simpsons’ malts for their roasted grains. Briess Chocolate malt has a lovibond of 350º, while Simpsons Chocolate malt has a lovibond of 400º-488º. Compare this to their roasted barley, where Briess has a lovibond of 300º and Simpsons has a lovibond of 488º-700º (quite the range).

Eric of Eric’s Brewing Blog  pointed out this Beersmith podcast with Randy Mosher, where (at around 17:30) Mosher discusses the range of lovibonds (somewhere between 150-225) that aren’t typically used because they create unpleasant ashy and burnt characteristics. He goes on to say the darker roasted malts, like Simpsons, are actually mellower than their lower lovibond counterparts. The higher temperatures actually burn those less-pleasant characters away. Interestingly, Mosher also notes that he dislikes Chocolate malt, equating it to “old diner coffee”, but Chocolate malt is incredibly widely used in both professional and homebrew recipes.

Either way, I think it is interesting that you get a different character from these roasted malts based on lovibond, and it is another thing I am adding to the experiment list. If nothing else, this validates my fear that large amounts of Briess malts may have been the culprit for some of the unpleasant characters in the beer.

Key Take Aways

Looking at all of this information, I see a few really important trends that seem like keys to building a better Russian Imperial Stout grain bill. These are things I plan on incorporating into my own brewing, and the research has definitely begun to shape what I think of as a “good” Imperial Stout:

  1. Diversify your roasted grains
    I think “startling” is the right word here. I didn’t expect so many of the recipes, almost all, to come to the table with a mixed presence of roasted grains, primarily Chocolate and Roasted Barley.
  2. Choose your maltster carefully
    This one I’m a little more hesitant about, but from the information so far I’m fairly convinced that maltster plays a siginifcant role in how the beer turns out. Choosing the right brand of Chocolate malt, in my opinion, can result in a very different beer.
  3. Keep your roasted grains around 8-15%
    The absolutely average of the amount of roasted grain used in the grist by Professional brewers is 8.3%. If you remove Old Rasputin, that average is 10%. In the homebrew recipes, the average is 11.2%, and with all of the recipes combined the average is 10.2%. I’m not saying a great RIS can’t be made with less than 8% or more than 15% roasted malts. Obviously, since I love Old Rasputin, that just isn’t the case. What I am saying is that, as a rule of thumb, that range is a good place to start construction.
  4. Use Crystal, and split it
    Crystal is an incredibly common ingredient in these recipes, and a few of them split the crystal, usually heavier on the C120 end of the spectrum than something lighter. Personally, splitting crystal is something I’ve advocated for a while now, and in my opinion is gives you a fuller, more complex caramel character.
  5. Be open to experimenting
    That list earlier of grains that were only represented in one recipe was extensive. I think that shows how open the style is, and that there is room to really dial in your preferences. When looking to build a grain bill, I’m definitely going to look more at specific grains I enjoy (like Honey Malt or Special Roast) and see if they play well.

There’s more to be learned from these recipes, and a lot to be learned outside of them (regarding Imperial Stouts, that is), but these four key factors are things that I think are going to help pave the way to a better grain bill design.

My Grain Bill

Based off of this research, here is my current grain bill (not counting things like maltster, lovibond, etc):

Base Malt 61%
Munich 10%
Chocolate Malt 7%
Roasted Barley 4%
Pale Chocolate 2%
Crystal 120-160L 4%
Crystal 20-60L;Honey Malt 2%
Flaked Oats 10%

Future Experiments

Let me continue beating the dead horse, this data doesn’t mean anything. It doesn’t prove that the only way to make a good RIS is with a blend of Chocolate Malt and Roasted Barley, it doesn’t prove that 2-row is a better base malt, and it certainly doesn’t represent the best practices of the community.

That said, it points to some interesting concepts, things that I want to (and encourage others) to experiment with and try to fine tune my own perfect RIS. As I continue this series, here are some of the things that are on my agenda to try out:

  1. Does a base malt of 2-row versus Maris Otter make a difference?
  2. Does the brand of 2-row (or MO) make a difference?
  3. Can a RIS made with Briess roasted malts be distinguished from a RIS with Simpsons roasted malts?

And, at the end of each of these, there’s the asterisk of “Which do I prefer?”. That’s what it comes down to when building a better beer, building it to your preferences so you’re satisfied.

In the next part of the series, we are going to examine hops and the hop-practices of breweries and homebrewers who make awesome imperial stout!

Cheers!

Resources

Reddit AMA with Oskar Blues Head Brewer Tim Matthews

Brew Your Own. “20 Beers for 20 Years”. September 2015

Reddit Homebrewing, for their awesome survey participation

Beersmith Podcast: Malted Grains for Beer Brewing with Randy Mosher

Past Parts of the Series

Part One: The RIS Survey

Building Behemoth: Reddit RIS Survey

I love Russian Imperial Stouts.

I’m not a beer collector or trader, but I’ll go out of my way for a good RIS. I horde Yeti and Expedition. My first homebrewed Russian Imperial Stout, the Black Loch, was the first beer I’d ever call “mine”, and it’s the first beer I ever won an award with. As a drinker and brewer, Imperial Stouts just have a special place in my heart.

Lately, my stouts haven’t been coming out too well. The roast character is either harsh or withdrawn, the alcohol character isn’t present, fermentation is sub-par. Not a great place to be, and I’ve blamed a lot of these issues on a lot of different causes. Maybe my roasted malt isn’t from the right maltster, maybe I’m not pitching healthy enough yeast, maybe my water profile is off. A lot of issues.

I didn’t have this problem originally, and looking back, thinking “what changed?”, the only thing that I can point to is me. As a brewer, I’ve changed. I formulate recipes differently, I take less risks, I’ve gone down the rabbit hole of “this is what will work” without identifying any of that theory in practice. I’m interested in practice.

This series will be all about building my next Russian Imperial Stout for the 2017 NHC. Tentative name for this dark monster is Behemoth.The point of this series is to look into how brewers (professionals and hobbyists) are making their Russian Imperial Stouts, what parts of the process they are making a point of doing well, and how I can implement those practices to brew a better RIS.

Reddit RIS Survey

In preparation for this series, I decided to contact the /r/homebrewing community and see how they were making their imperial stouts. Particularly, I wanted to see how common certain trends were, and if there was anything I could pull from the data that would validate some of the other information I’ve gathered.

Note: This survey is just a survey, it isn’t saying anything definitive about imperial stouts, it’s not scientific, it isn’t meant to “do” anything or make a specific argument. More than anything else, I think this data is interesting. I would not recommend making a decision for your next brew based off of this data, because everything is tied to the individual recipe. If your yeast is REALLY attenuative, you may need to make an effort to set up some unfermentable sugars. If you want some esters in your beer, an English yeast may be the way to go. All beers are different, and the individual beer will call for its own ingredients and process. Personally I used this data as a guideline, looking at variables I’d like to try, taking notes from batch to batch, and really dialing in the recipe.

Mash Temps

As part of the survey conducted on /r/homebrewing, I was interested in the mash temps brewers are using for their RIS. The common knowledge says that a lower temperature will give you a more fermentable wort, leaving behind less body and sweetness, while a higher temperature will do the opposite, creating unfermentable sugars which contribute to body and sweetness.

 

rischart

It’s always interesting to me how most people gravitate towards even numbers.

So the absolute average out of 97 responses here is 153.8°F, so around 154°F. 

Malts

Base Malts

The two most common types of base malt used were 2-Row and Maris Otter. It’s said that Maris Otter (which is a variety of 2-row) imparts a “biscuit” character, is somewhat heavier than standard 2-row, and it’s often favored in English beers. 2-Row is lighter and is often the base malt for an American beer. Being such a large portion of the grain bill, I was curious why people were using the base malt that they were usingbasemalts

60 people responded that they use standard 2-row as a base malt. The reasons included:

  • Specialty malts are the focus and comprise most of the flavor
  • Cheaper
  • Already own it in bulk
  • Prefer the clean character
  • Prefer American-style RIS
  • Higher (on average) diastatic power

20 people responded they use Maris Otter. Reasons include:

  • Prefer the biscuity quality of the malt
  • Many recipes they have seen use it
  • Preferred English base malt
  • Better malt profile overall
  • Slight nutty quality

Others note a blend between MO and 2-row, or a blend of MO and Munich, or even just using Golden Promise as the base malt.

Far and above, we see people answering that they use 2-row. This is a self-select survey, people opt in to take it, so I wouldn’t by any means claim it represents the homebrewing community as a whole, but it’s definitely an interesting point of data. Until now, I’ve only used MO in my Stouts, but after the overwhelming response from the community (and fantastic notes from Tim Matthews I’ll discuss in a later part of the series), I’m on board, at least enough to add it to the list of experiments.

Roasted Grains

When I was critiquing my own RIS, one of the first reasons I jumped to for not having the roast quality I wanted was the brand of roasted malt (Briess) I was using. It made sense to me that an inferior malt would produce an inferior product, and that’s not to say that Briess is default inferior, but that it wasn’t the malt for me and my RIS.

After reading a response from Tim Matthews who said that they (Oskar Blues) use all Simpsons roasted malts, I was even further convinced that the malt was the issue. Now I’m not so sure, but I do think the question of malt variety is interesting, and wanted to see if other brewers paid attention to it in a malt forward beer like a RIS.

brandraosted

Some of the “Other” responses were stating the blend they use, or that they toasted their own. Also, one vote for Bairds malts and two votes for Crisp, which weren’t represented on the survey.

I found it really interesting that most brewers either didn’t pay attention to the malt they were using, or used a blend of roasted grains. I should have gone further and asked more about the grains, /u/TestingApril of the blog In Bounds Brewing suggested having a checklist option for all of the brands and their malts, which I definitely should have done. If this survey is ever re-done, that’ll need to be implemented.

I’m still convinced that maltster plays a role in the final beer, but it’s worth testing. That may be the next experiment, whether Briess Roasted Grains and Simpsons can be distinguished in a RIS. For now I’m thinking yes, and I’ll be using Simpsons.

Hop Additions

I should have asked when the additions were as well, my guess of “bittering and aroma” probably doesn’t hold true for all, or even most, of the recipes here. What is interesting is the massive margin that 2 hop additions wins by.
hopadditions

Personally, I use 2 additions now and I don’t see a reason to change it. A bittering addition and then a 10 minute addition works well. Hops, in my opinion, just shouldn’t stand out in an Imperial Stout. I’ve had some “hopped up” stouts like Pipeworks Brewing’s Close Encounter, and they can be good, it is just not what I’m looking for in an Imperial Stout. More than anything, I’m paying more attention to the research portion of this article, listed above. My plan is to stick to two hop additions, maintain a good IBU/OG ratio, and experiment with high versus low alpha acid hops.

Yeast Selection

As someone who collects yeast like some people collect stamps, I found these results incredibly interesting.

yeastchoice

A vast majority of survey participants selected US-05 as their go to RIS yeast. Those who opted to give a reason said it was because it was a clean-fermenting yeast, readily available, and it’s easy to make sure you are pitching enough cells. Most participants who noted more than just their yeast selection made a point to note they used their yeast because it was either clean or had a good ester profile, a pretty clear line between an English or American selection.

Personally I really enjoy Scottish Ale Yeast, WYeast 1728. It’s attenuative, versatile, and it has a romantic place in my heart as the yeast I used in my first beer that won an award. That said, I’m heavily biased towards the yeast and the idea of not using it makes me a little uncomfortable. Pretty clear sign that it’s something I need to experiment with and take a step back to reevaluate.

Like the other results though, yeasts are tied to their recipe. There isn’t a good way to “test” yeasts against each other because they may excel in different worts, as different beers. All about personal preference. I will say, from the professional list above, I tend to enjoy the beers made with Chico than yeasts made with English strains. I’m going to need to look into it, but in the re-design of the beer I’m going to experiment with a yeast like US-05 or WLP090. Part of refining your tastes is letting go of ideas you’ve held in brewing in favor of a subjectively better beer.

Aging

The dogma of “Imperial Stouts improve over time” comes up pretty often in the research I’ve been doing, and I’m curious to see who intentionally ages as a part of their process.

Out of 100 responses, 83 people said that they intentionally age their RIS, and the average intentional aging time was 3 months. Most people aged at least one month, what really threw the average was the few people who intentionally make a yearly batch, and age for said year.

Reasons for aging were:

  • Mellow out the alcohol character
  • Mellow the roasted grains
  • Complexity in general
  • “Because others do so”

By far, the second bullet. Easily the most common answer.

I loved doing this survey, it was awesome to see how some homebrewers are treating recipe construction and what they consider important for the style. If nothing else, this survey will be used throughout the series to either reinforce the other data, or to show how “rules” may not always be the case in practice.

Next time, I’m going to look into grain bills from professional brewers and past NHC winners to see how they are building the grain bills of their stouts.

Cheers!

 

They Did the Math: Formulas and Calculations for Barrels and Alternatives

I don’t have a mind for numbers. I love the idea of math and theoretical puzzles and problem solving, but I just can’t wrap my head around the numbers. If you’d like me to mimic the stand up routine I saw once last year, I’m your guy, but I most definitely couldn’t tell you the formula that I learned a few hours ago. I’m sure this is self-fulfillment on my part, I don’t think I’m good at math so I’m not, but really it’s been that way as long as I can remember.

When I was getting into brewing, seeing all of the numbers involved was frustrating and daunting. I remember looking at a “build your own recipe” sheet which had you work backwards from gravities and SRMs to make your grain bill. Then I had to figure out efficiency, attenuation, hop utilization, all those good old formulas that play central rolls in brewing good beer.

Thank God for calculators. I don’t know what I would do without them.

I’d learn the math eventually if need be, but you just can’t replace the convenience of BeerSmith or a good yeast pitching rate calculator.

Unfortunately, in wood aging, there aren’t many calculators out there for the sort of work we are hoping to do and so I had to look into the math myself.

Barrels: Paraffin Wax

IMG_20151201_213501263-223x350Let’s say I buy a barrel, 5 gallons, and rack a nice English Barleywine into it. Per all of the barrel aging instructions I see, I let it sit for a year, topping off the Angel’s Share. After that year, I sample, and the oxidation is intense to the point where it could pass as an Old Ale, but would definitely still be labeled oxidized because of the heavy sherry/port characters. And we haven’t even mentioned the overpowering oak and rye alcohol characters.

True story.

So what happened? Not all barrels are created equal, especially when it comes to barrel sizes. See, in the barrel, oxygen is exchanged through the wood. That oxygen exchange is often desirable, but as we see in our example it can quickly get away from you. The issue is that I treated a 5 gallon barrel like a 53 gallon barrel, and didn’t account for the higher oxygen exchange rate.

I also didn’t calculate out the surface area, and the wood was overpowering in one instance where it may not have been in another.

To solve this problem, a lot of brewers will cover a portion of their barrel in paraffin wax. Paraffin wax is a food-safe wax that we can use to cover a portion of the barrel, “sealing” it and lowering the rate of oxygen exchange. By doing some pretty simple math, we can approximate how much of the barrel we need to seal in order to mimic the exchange rate of a larger barrel.

This formula is by no means perfect. A barrel is a parabola, and I typically use the formula for a cylinder. Like I said, this is an approximation, the goal is to get close. I’ll update once I figure out a better way to go about this process. I’ve looked into the parabola formulas, and that is a bit beyond me. The formula for surface area of a cylinder is:

πdH + 2( πr2)

Where d is the diameter of the head of the barrel, H is the height of the barrel, and r is the radius of the head of the barrel (or half the diameter).

I originally saw this formula used by /u/brouwerijchugach, author of the blog Brouwerij-Chugach and incredible brewer of all things sour. Basically, by using this forumula, you calculate the surface area of the barrel (in square inches) and place it against the surface area of a full sized barrel, which helps you estimate the approximate aging time compared to a full-sized barrel, thus determining what percentage of your barrel you need to paraffin wax in order to replicate the oxygen exchange (which will lengthen the aging time). Now with edits from Eric of Eric’ Brewing Blog! Canadian Brewer extraordinaire, who pointed out that the formula failed to take volume into account.

To determine the percent of the barrel you need to paraffin wax, multiply the surface area of a full sized barrel by the volume of your small barrel, multiply the full size volume by the surface area of your new barrel, divide those numbers, and multiply by 100. Then, subtract that number from 100 and you’ll have the percent you need to wax. Expressed as:

100 – (((3066 * Volume of smaller barrel) / (53 * Surface area of smaller barrel))* 100)

In practice: You’ve got a new 10 gallon barrel that has a head diameter of 14″ and a height of 18″. Plugging these numbers into our formula, you determine that there are 1099 square inches of surface area. Your standard whisky barrel is usually 53 gallons, with a 21″ head diameter and 36″ tall, which works out to be about 3066 square inches.

100 – (((3066 * 10) / (53 * 1099)) * 100)

100 – (((30660) / (58247)) * 100)

100 – (.526 * 100)

100-52.6

47.4%

So, to replicate the larger barrel, you would need to paraffin wax roughly 47% of the barrel.

Barrels: Aging Time

So what if you don’t want to paraffin wax? I don’t blame you. It’s a messy project. But you’re left with the problem that the oxygen exchange is going to be more rapid since your surface area to volume ratio is higher. So, the obvious answer is that you’ll want to age your beer for less time so it isn’t oxidized beyond redemption (my own sour stout comes to mind. Blegh.)

In the last step, instead of subtracting and multiplying by 100, you multiply by 365. That’s your aging time. So calculate out the surface areas, and then instead of the previous equation you would use:

365 * ((3066 * Volume of smaller barrel) / (53 * Surface area of smaller barrel))

In Practice: We have our freshly used 10 gallon barrel, with a surface area of 1099 square inches. Plug that into our formula, and instead of covering 47% of the barrel, we can age for 192 days.

365 * ((3066 * 10) / (53 * 1099))

365 * (30660 / 58247)

365 * .526

192 Days

Now, in loose and unexamined theory, these two methods would give you the same finished beer. They will not. Oxidation isn’t equal, and a beer aged for 3 months isn’t the same as a beer aged for 12 months. Also, paraffin waxing does nothing for the oak characters in the beer, which are still fresh and will be stronger in a smaller barrel due to the higher surface area to volume ratio. Those issues need to be addressed themselves.

Barrel Alternatives

This is less a formula, and more an explanation that I found interesting. A friend, /u/Chino_brews of Reddit, brought up in the BrewUnited forum that barrel alternatives (cubes, specifically) are used in different quantities than full sized barrels in terms of surface-area to volume ratios:

This blog post seems to indicate that a 59-gallon wine barrel corresponds to a barrel surface area to volume of 54 square inches per gallon.

 

It seems like an oak cube averages around 0.75 square inches each (they average around 0.5″ x 0.375″ x 0.25″ based on my samples). So 72 cubes per gallon? That is about 10-11 oz. per 5 gallons and seems way out of line with recommended usage rates.

 

This article from MoreWine suggests that 2.5 to 3.0 ounces per gallon corresponds to “new barrel” extraction rates.

All of my research has pointed to my recommended usage rate of about 1-2 ounces of cubes for 2-4 months in a 5 gallon batch, so way less than Chino’s math suggests, and a little less than the MoreWine suggestion (which is for new barrels, which tend to have a higher extraction rate). So why are these numbers not even close? Starting by re-doing the math to make sure it is sound (using our 53 gallon whisky barrel):

3066 square inches / 53 = 58 square inches per gallon

58/ .75 = 77 cubes per gallon

So that checks out, 77 cubes per gallon (or roughly 13-14 oz of cubes for a 5 gallon batch) is way more than any recommended rate I’ve seen. What gives? Why are barrel alternatives not in line with barrels? Why aren’t the surface areas at least somewhat equal?

In my in-no-way-beyond-question opinion, the answer is penetration and grain. In your average barrel stave, beer will typically only penetrate up to 6mm. Our surface area calculations earlier do not account for the penetration, just the initial surface. With staves, beer is only in contact with one side, and so it only sinks in those 6mm and then stops (not really, more goes on with oxygen exchange but for the purpose of the explanation it stops). But cubes are different, they are submersed in beer, so they are thoroughly soaked in beer. The 6mm penetration is on all sides, and so there is more going on in the core of the wood than with a barrel.

Think of a stave from a barrel. If your average homebrew stave addition is about 8″ tall and 1″ in diameter, it has a surface area of about 27 square inches. In a barrel, the length of that stave would be in contact with the beer, but the width would only be penetrated up to .2 inches on one side. That’s a lot of stave that isn’t in contact with the beer. But out of the barrel, sitting in your fermenter, that stave is penetrated .2 inches on all sides.

The other issue here is the grain of the wood, pointed out to me by Chris of Northern Brewer. If you’re not familiar, the grain of wood refers to the direction of the wood cells and the cut of the wood. These are typically three categories: end grain, face grain, and side grain. If you look at the wine barrel stave image on the right, you’ll recognize the three. On the “top” of the stave, you’ll see the face grain. The sides of the staves are side grain, and the slanted part where the wood was cut is the end grain. The part of the stave that is in contact with the beer in a barrel is the face grain, and liquid penetrates this part of the wood up to eight times slower than the end grain.

Cubes, however, have all the grains. They’re chopped up, all faces are present, and so in addition to being penetrated more thoroughly, they are also penetrated quickly because of the exposed end grains.

The fact of the matter is that barrel alternatives are just not the same as barrels. I’m a huge advocate for barrel alternatives in homebrewing, but they aren’t a perfect substitution.

As pointed out by Matt of the blog Accidentalis Brewing, temperature fluctuations also come into play here. Barrels are often exposed to more extreme (relative to wood additions) temperature fluctuations than wood additions, and the hot/cold shift can cause the grains to expand/condense, adjusting the rate at which liquid penetrates the wood. Often, wood additions are in the same temperature controlled environment as the primary fermenter, and the pores of the wood are not changed as often.

Couple this with the fact that the surface area of wood additions and the surface area of barrels exist in different conditions. Barrels are the vessel. They aren’t just used to add wood character to a beer, they’re used to store a beer, and as such, they have contact with oxygen that the barrel alternatives don’t have. The oxygen exchange, also affected by those temperature fluctuations, changes the character in your beer.

The oxygen exchange of barrel additions is negligible, only the oxygen in the addition matters and it is near zero. The exchange of a barrel versus the exchange of a plastic fermenter versus the exchange of a glass fermenter are all different, and so this exchange obviously impacts the time you want to age your beer to get the same character, keeping in mind that a beer oxidized quickly will be different than a beer oxidized slowly.

God Bless Calculators

1-15-2016 10-52-15 AMIf, like me, you don’t like math then this will help you out.

I don’t have the knowldge to code something into WordPress to make a live calculator for the site, which would be cool, but I put together and excel file that contains the formulas I’ve used in this article:

  • How much to paraffin wax a barrel to simulate a 53 gallon whisky barrel
  • How long to age your beer to get similar oxygen exchange as a larger barrel
  • How much of a barrel alternative you should use

I’ll update the spreadsheet as it goes on, and it might turn into something else, but for the time being, the spreadsheet can be found here.

Now, like the formulas it is based off of, the spreadsheet is an approximation. Always take notes, always dial in your individual preferences and system.

Cheers!

Matt

Homebrew Wood Additions and Barrel Alternatives

I imagine most people, like myself, see the term “oak-aged” and automatically assume the term is synonymous with “barrel-aged”. When I first started looking into using wood in my homebrewing, I spent a long time looking through the various sizes of barrels available and concluded there was no way I’d be able to sell this to my SO, and even if I could, I didn’t have the space in my tiny apartment.

My local homebrew shop carried oak chips. When I was talking to the owner about my plans to make a wood-aged Imperial Stout, they pointed me towards the chips they carried. They were medium-toast chips, about 4 oz, packaged by the homebrew shop from what I imagine was a larger bag. I was told to boil all 4 oz for about 10 minutes, then add the chips to a secondary fermenter and rack the beer on top of them.

“But how long do I let them sit?”

“I like to leave mine for a few months, really let the flavors mellow and blend.”

Well, what did I know? So I did, secondary and all. What I got was an oak-bomb, all tannic wood character and some slightly oxidized imperial stout. I wasn’t thrilled, and kept thinking that there had to be a better way to wood age.

After some research, I not only learned that I had used way too many oak chips for far too long a period of time, but that there were fantastic barrel alternatives out there for homebrewers who don’t have the space for a barrel, don’t want to dedicate a full batch to wood-aging, or don’t want to drop the money on a barrel you may only use a few times.

The Barrel Alternatives

Chips

Chips are thin, small, flaked pieces of wood. They have a large surface area-to-volume ratio (lots of wood in contact with the liquid), which, as I learned the hard way, means they impart their flavor very quickly. Because they are so thin, chips are toasted fairly evenly. Toasting takes place on both sides of the chip and heat penetrates the wood easily. As a result, the flavor imparted by wood chips is said to be rather one-dimensional, reflecting the singular toast of the wood. This is not necessarily a bad thing, and at times a subtle, one-dimensional flavor may be useful, especially if wood is not intended to be one of the heavily present flavors of the beer (for example, Old Ale or Flanders Red can have some wood character).

Cubes

Cubes, also often called beans or tablets, are segments of wood that have been cut into larger chunks. Because of their size and shape, cubes have less surface area-to-volume than chips or powder, and they take longer to impart their flavor to beer. Since they are more dense, the toast on the outside of the cube does not necessarily reflect the toast of the inside, since heat would take longer to penetrate the wood. This means that, when aging, the longer the cubes are in contact with the beer, the more complex the imparted flavor will be, since the different levels of toasting will impart different flavors. The obvious con is that this takes more time than powder, essence, or chips, and the pro being that, since flavors take longer to be imparted, they can be controlled more effectively by sampling over a longer period of time.

Essence/Extract

Essence is essentially a commercial wood extract that can be added to your beer, often at bottling. Since it is an extract, it is made to impart the oak flavor into your beer incredibly quickly and no aging is necessary (the wood flavor will still mellow overtime). Like chips, the flavor imparted from essence is often perceived as one-dimensional, even more so. Essence is fast, relatively cheap, and effective for what it is.That said, some users have reported that the extract tastes “artificial”. Not sure what to take from that, but there it is.

Honeycombs

Honeycombs are a fairly recent development, one I am particularly excited about. I love honeycombs. They are similar to staves and spirals, in that they are long segments of wood. However, the segments have holes drilled into them. This means a larger surface area to beer ratio, which means flavor is imparted faster, but not so fast that you’ll lose track of the flavors. My favorite part about honeycombs is that they are typically available in a much wider variety of woods than other types of additions, which means less work for you.

As far as I can tell, the honeycomb has been pioneered by Black Swan Cooperage. They have nine types of honeycombs available, along with guidelines for using them and details about the sort of characteristics that the wood can impart.

Powder

Powder is a dust that is added to beer a day or so before bottling. The beer will permeate it quickly, and it will sink to the bottom. Because of the rapid permeation, the flavor is extracted incredibly quickly. As you can imagine, powder has the highest surface area-to-volume ratio of the natural additions (all the listed additions besides extract). Powder has the potential to be incredibly one-dimensional to complex, depending on the toast(s) of the wood(s) the powder is taken from. However, the complex flavor from powder is itself often reported to be rather stale when compared to the flavors of cubes, spirals, and barrels. Besides extract, it is the hardest addition to separate from beer.

Spirals

Spirals are long, circular segments of wood. Because they are one solid segment, their removal is often incredibly simple. Commercially they are often more expensive than chips or cubes. Spirals are often said to impart a smoother, better flavor than cubes, quite possibly a result of having less surface area-to-volume. Spirals are often associated with vintners more than homebrewers, however they are still a valuable addition.

Staves

Staves are similar to spirals in their use since they are single addition; however how they are made is different. Staves are often smaller sections of wood cut from larger staves, the ones used in barrels. Typically, these staves are cut from the length of the stave, so the broad side of the stave will reflect the red layer and the outer layer. They are generally thicker than spirals, but some staves are relatively thin. Size is an important consideration, because it affects how much wood character you will get from the addition and how quickly.

How much should I add?

Really, it depends. There is no hard and fast rule to adding wood to your beer. You need to consider how much flavor you want, how long you want to age, what sort of addition you are using, and so on. Its variable. Below is my “rule of thumb” guide for the additions to a 5 gallon batch. If you’re not sure where to start, the table will help you out. What I’d like to emphasize here is to take notes, measure how much you add of a certain addition and for how long, and then reflect on the wood character in the beer. Do you need less? More? Different wood? Consistency is key, figure out what works for your process.

Addition How much? How long?
Chips .5 ounces About 1 week
Cubes 1-2 ounces 2-4 months
Essence/Extract Noted on the bottle, depends on the extract Used at packaging
Honeycombs 1″ of Honeycomb per gallon of beer 4-6 weeks
Powder 1/8th to 1/4th an ounce One to two days, due to incredibly high surface area-to-volume
ratio. Two days is pushing it.
Spirals One 8″ spiral 1-2 months
Staves One 8″ stave 2-3 months

How should I add them?

There are a variety of ways to add these various additions to your beers. It comes down to your personal preferred method and the sort of character your are looking for.

Straight Addition

A straight addition involves adding the wood directly to your beer. Just add the desired amount to your fermenter (or whatever you plan to age in) and let it go.

This is my favorite way of adding wood to beer. It is simple, quick, and leaves you with that romantic wood aging feeling. It is also effective, and makes sure that you get a bit closer to that authentic (aging in a barrel) method that some people may hope to get closer to.

The obvious issue with this method is sanitation, since nothing inherent in the method sanitizes the wood. Two preferred methods here, depending on the sort of wood you’re using. If the wood is fresh, I recommend you boil the wood for ten minutes. This will not only sanitize, but it will also get rid of some of the tannic qualities that fresh wood can impart. After boiling, just add the wood to the fermenter and get rid of the liquid. The second option, with wood that you’ve used before (typically, this will be staves or spirals), you can put the wood in the oven at around 170F for ten to fifteen minutes. Technically, sterilization temperatures are around 200F, but even at 170F you’re affecting the toast of the wood a bit.

Tincture

For this method, simply put your wood and enough alcohol to cover it in a seal-able container and let it sit. Two weeks is a good rule of thumb, but the longer the better. When you are ready to bottle, gently pour/siphon the liquid into beer, tasting as you go. When you have the level of flavor you would like, stop adding and then gently stir your beer so the tincture is evenly distributed. Once that is done you can go ahead and bottle!

What I like about this method is that it allows you to control the flavors of your beer relatively easy. When you have the character you’d like, just stop. Simple.

You can use whatever liquor you’d like, most often I see people using vodka or everclear since they are relatively “flavorless”. You can also use bourbon, whisky, rum, or whatever else you’d like to have a presence in your beer.

In my opinion, you should be using vodka no matter what characters you want in your beer. If you want a bourbon barrel stout and plan to use a tincture, add the vodka-wood tincture and the bourbon desperately. This will allow you to control the levels of each, independent of one another. Combining them doesn’t give you any benefit. Same recommendation for those who plan to age their beer on wood and want bourbon character. No need to soak the cubes and then age on them, just age on the cubes and add the bourbon at bottling.

Photo Credits

Oak Chips from Love2Brew.

Oak Cubes retrieved from Brew Brothers.

Honeycomb from Adventures in Homebrewing.

Spiral from Philly Homebrew Outlet.

Toast versus Char

Toasts and Chars

After the initial release of the Wood Primer, my work on it fell behind and stopped altogether while I focused on articles for other sites and took over some of the moderation responsibilities over at /r/homebrewing, notably, the Reddit Homebrewing Competition. I’ve also been working on something called “The Brewery”, something I’ll post about later.

Really, I think the most valuable part of this blog is the wood primer and the exploration of brewing with wood, which is the reason this blog started. Here we are hosting move and a year later, and it’s time to refocus and get back to why we are really here.

Every now and then, I’ll get an email or message about a specific wood question, and one of the ones that comes up pretty often is “What is the difference between toast and char?”, something that wasn’t even mentioned in the original primer. I took some time to really research this one, and to test it out myself utilizing some awesome resources, quite a few provided by /u/chino_brews.

So, what are they?

Toasting and charring are two ways that barrels are treated prior to being used. Basically, toasting creates the “red layer” but doesn’t necessarily change the surface of the wood in a drastically noticeable way aside from color. These toasts change the chemicals in the wood, giving the barrel certain characteristics that can be imparted to the barrel’s contents. Charring can also create a red layer, but more importantly it creates a much heavier layer on the outside of the wood because the wood catches fire. So both of these steps change the composition of the wood, and changes the characteristics the barrel can impart, but the key difference is that toasting rarely involves the flame contacting the wood for any extended period of time, while charring involves the wood catching fire.

Toasting

Barrel being toasted. 

Toasting typically occurs before the charring process, and takes places over a longer time with a smaller flame. As seen in the image on the right, the barrel is placed over (but not in contact with) a flame so that the inside of the barrel is heated. This heat “toasts” the wood, and breaks down chemicals, namely lignin, cellulose, and hemicellulose. The breakdown of these chemicals causes different flavors and aromas to develop, which can then be extracted into the barrels contents. You can read more about toasting and the chemical changes in The Big Wood Toasting Post.

 

Charring

Barrel being charred. 

Charring is a short (the intense “alligator char”, or char #4, only takes about 55 seconds), high-heat process that creates a level of char (Char #1 through Char #4) which “chars” the wood and causes it to crack. The purpose behind charring is two-fold: The first is that the char creates a sort of natural carbon filter which absorbs sulfur compounds, and the second is that the cracking caused by the char allows the barrel’s contents to penetrate the wood. Charring also tends to develop a small layer of toasted wood, called the “red layer”. Barrels may or may not be toasted before this step as well.

The levels of toasting and char vary greatly depending on the vintner/distiller and the barrel’s contents. For example, in the U.S., bourbon must be stored in charred oak containers, while corn whisky does need to be in a barrel (new or used), but not necessarily in a charred barrel.

If you read the Big Wood Toasting Post, you’ll remember that the heat in the toasting process causes cellulose, hemicellulose, lignins, and other compounds to break down and create different flavors/aromas from the barrel. Charring works the same way.

Char levels.

The four traditional char levels are Char #1, #2, #3, and #4 which is also referred to as “Alligator Char”. The lighter chars tend to be “spicier”, with more of those sweet and oak characters we get from a low-medium toast. Darker chars tend to be a bit more toasty and will have more prominent vanilla characteristics.

Charring at home

I’m all about DIY solutions, especially when it comes to brewing. Getting down a solid toasting process is something I’ve spent quite a bit of time working on, and I’d never really addressed using char in homebrew.

One of my favorite beers (by one of my favorite breweries) is Serpent Stout by The Lost Abbey. It’s thick, full of bitter chocolate and bold roast flavors. All around a great beer. When I first had it, there was a quality I couldn’t quite place, some what acrid and sharp, but still pretty wonderful. The flavor seemed at home in a stout.

I did some research, in their QR code (RIP random kitten) they mention that a portion of the beer (10%, according to this recipe from their lead brewer [supposedly] and this information from their microbiologist) is fermented in freshly emptied bourbon barrels which, as we know from earlier, are required by law to have a char (typically a #3). According to those sources, the char is where those flavors come from.

And of course I had to try it out.

Around the time I was planning the beer to test this I was contacted by Rex of The Brew Bag to see if I’d like to review the Brew Bag. Rex is a sponsor for RHC (and is giving away some custom Brew Bags!), and I’d read a lot about the Brew Bag from other reviews. I was eager to try it for myself, so I agreed. You can read more about my review and experience with The Brew Bag here. No affiliate links or anything, just love for a great product!

Charring is pretty simple. Get some wood and the appropriate toast, with the idea that the layer on top will be a bit darker than the toast throughout. This is a good thing, because the char will open up the wood a bit and the layers of toast will provide more complexity.

Get a torch, light ’em up. The short, high-intensity flame is what you’re looking for, you can use the chart above as a guide to the char levels. The wood will catch fire, don’t worry about it, keep the pressure on.

Once you think you have the cubes where you want them (feel free to char one side, or all sides), go ahead and blow the fire out and let them cool. Charred wood!

I ended up boiling the cubes at this point, it was something I wrestled with. On one hand, I didn’t want the tannic, strong oak flavors from the wood and since I am using them in primary they need to be sanitary. I have my doubts that my makeshift charring killed everything. On the other, I don’t want to remove those acrid sort of flavors I’m looking for from the char. I decided sanitation was more important, and boiling is how I typically sanitize anyways.

I ended up splitting 6 gallons of my Black Loch RIS, 3 gallons fermented on the oak cubes I charred and 3 gallons on nothing. I left both beers in primary for about 6 weeks, which is a little shorter than I usually advocate for aging on cubes, but just about where I usually bottle this specific beer.

Even before bottling there was a difference in the beers. The batch fermented on the charred oak cubes had a sharp roast flavor that had a relatively smooth finish. I really enjoyed it, but I didn’t want to come to any conclusions without having both beers bottle condition for a few weeks and be chilled. In my experience, pre-carbed beer isn’t a wonderful indicator of the final product.

I bottled both batches, let them sit for three weeks (not long enough, IMO), and set them in the fridge. A few days alter I opened both.

The Review

Color was identical, both were black and opaque with a dark tan head, a bit creamy. The aroma was also pretty identical, I had the beers served to me blind in a triangle test multiple times and couldn’t tell a difference. I was hoping for the char to come through a bit here, but I’d guess a lot of the aromas left in primary. Or it just didn’t change aroma, who knows.

I’d like to say there is a clear difference in the beers, but I’m honestly not sure. In five triangle tests, I reliably selected the odd beer out. However, I also let a lot of friends sample the beers and they couldn’t tell the difference. Note that it wasn’t a blind triangle test, they knew the beers were different, but they didn’t see it. It’s entirely possible I only selected correctly because I knew what I was looking for, and it’s also possible that I selected the odd beer correctly each time out of luck (really not that hard to do with a sample size of 5).

In my opinion, the beer fermented on the charred oak had a sharper characteristic in the roast, just like at bottling. There was definitely some wood character, a toasty quality that I’ve come to love from medium to medium-heavy oak American Oak. There wasn’t really an acrid characteristic like I was looking for, but I absolutely felt that the roast was a bit sharper and more complex than the ample amounts of roasted barley and chocolate malt I usually use typically deliver.

It occurred to me early on that I should test the char in another way, and so I also soaked some of the charred oak in vodka, alongside some medium toast oak cubes that hadn’t been charred. Sipping the liquors, the charred batch was darker and more defined, but I wouldn’t say sharper. Almost smoother honestly. The medium toast batch was a little sweet, oaky, and had hints of vanilla, characteristics that were far more restrained in the charred batch.

I really think the char contributed to the beer, and it’s something I’m going to dedicate more time and official tests to it in the future.

Conclusion

Toasting and Charring are two ways to get different characteristics our of your beer. Changing these attributes opens up the sort of contributions you can get from the wood, and understanding the role of different levels will help you find narrow down the wood you’d like to use for your beer. This post wasn’t really meant to be a comprehensive post on charring, and it isn’t by any means, just to introduce the differences between toasting and charring and starting down the path to exploring these concepts further.

Cheers!

Matt

Resources

https://books.google.com/books/about/Craft_of_Whiskey_Distilling.html?id=t75rPgAACAAJ&hl=en

http://seguinmoreaunapa.com/charring_bourbon_barrels/

http://www.iscbarrels.com/char-options

http://australianbartender.com.au/2013/03/20/lock-stock-smokin-charred-barrels/

http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&sid=21224b7c634d83e0fa329bfd18bb85dc&rgn=div8&view=text&node=27:1.0.1.1.3.3.25.2&idno=27

http://www.drinkspirits.com/whiskey/jack-daniels-barrel-making/

Toasted barrel image retrieved from: http://www.wineanorak.com/howoakbarrelsaremade.html

Charred barrel image from: http://seguinmoreaunapa.com/

Char levels image from: http://www.iscbarrels.com/

The Brew Bag Review

My typical brew day goes something like this:

Wake up fairly early, grind coffee with my manual burr grinder, and get that going. Since I’ve printed out my recipe and measurements the night before, I double check that I have everything I need: water, grains, hops, mineral additions, etc. By this point, the coffee is done brewing. I drink it black.

Coffee in hand I start heating the water and cleaning/sanitizing whatever needs to be cleaned, which typically only involves cleaning out the mash tun (I don’t sanitize this). My mash tun utilizes a bazooka screen as its filter. Once the water is around 180F, I dump it in my mash tun and seal it up for five minutes to let the interior of the mash tun warm up. Then, I open the mash tun and let it cool to my target temperature. Add grains, stir with my giant whisk, check temp, pull a pH sample, seal it up, stir every twenty minutes. I usually lose a degree or two over the course of the hour long mash. Drain, vorlauf, sparge, begin boil. Pretty straight forward.

I love on the second floor of an apartment building, and I’m a stove-top brewer (not for much longer unfortunately). And, for the hell of it, I really enjoy high gravity beers and end up making 6 gallon batches on those big brew days. That means that after my sparge, I’m left with about 26 pounds of spent grain in my mash tun. Usually, I’ll scoop the grain into a trash bag, put the trash bag in the cooler (in case it breaks), carry it all down the stairs, across the parking lot, and dump everything in the dumpster. It is a pain, but the best method I have right now. The bazooka screen I’m using has also had a stuck sparge or two, isn’t that fine a mesh, but to its credit hasn’t been crushed at all despite everything I put it through.

While coordinating some awesome sponsors for the Reddit Homebrewing Competition, I was contacted by Rex of The Brew Bag who asked if I’d like to review a Brew Bag. I don’t have any ads or affiliate links on this blog, so I’m skeptical to review things, but I’d been wanting to give a Brew Bag a shot after reading reviews from Brulosophy and Brew United, so I agreed and Rex shipped me a Brew Bag to try out.

The Brew Bag (aka Rex) is also a sponsor of the Reddit Homebrewing Competition this year and is offering three brew bags (any size) and 3 pairs of gloves. Awesome deal, so if you’re entering the competition check out the reviews to learn more!

Here’s how I feel

For this brew day, I made an American Stout with the intention of fermenting the wort on charred oak cubes. Luckily, the Brew Bag arrived at my house the day before I intended to brew so I was prepared to give it a shot, I removed the bazooka screen from my mash tun that same night.

It isn’t what I expected. It was custom to the size of my mash tun, which was cool, but I had expected it to be something closer to a large muslin bag, but the mesh in the brew bag is light and incredibly tightly woven. I can’t imagine any grains slipping through it.

Unfortunately, I made a mistake pretty early on. I poured my heated water into my mash tun and went to take a temperature reading. I’m a fairly clumsy human being, I’m increasingly surprised I’m allowed to handle glass, and I just wasn’t paying attention. When I put my thermometer into the water, it punctured the Brew Bag a bit. It doesn’t take much pressure from a thermometer to puncture the mesh bag, but it was a small hole and I wasn’t worried.

I mashed in, used my whisk, and all was well.

When I drained my mash tun, I didn’t remove the brew bag since I would be adding sparge water. At first, I opened the ball valve and nothing came out, it took me a second tor realize that the bag was blocking the valve.

I opened the mash tun and pulled the two handle from the front of the cooler to the back, pulling the grain to the back along with it, and closed the mash tun on the handles. Worked like a charm.
I prepared to vorlauf, and immediately abandoned the idea once I started. There wasn’t a single grain in the liquid, color me impressed. This thing really got the job done.

I ended up collecting more volume than I had anticipated, most likely a consequence of failing to adjust my equipment profile to account for the bag. Not a big deal, but I ended up with 6 gallons of wort post-boil rather than 5.5, but still ended up getting slightly above my intended OG (got 1.056, wanted 1.055). This took my typical 72% efficiency to about 78%, which is awesome.

Clean-up was basically heaven. I told you earlier about my typical pain of a process. This time around, I just picked up the cooler, walked it down to the dumpster, and turned the grain bag inside out. Sure, carrying it is a pain, but it was simple and quick. This alone sold me on it.

Should I buy one?

Pros

  • Pretty durable when it comes to grain. The hole I made with me thermometer didn’t stretch any bigger, but this may be because I didn’t really apply more pressure to it.
  • Works really well. I didn’t have a single grain in the boil, it was fantastic.
  • Clean up is super simple.
  • My efficiency went up, which is great, and it will be even better when I have adjusted my equipment to use the bag.

Cons

  • You can poke a hole in it pretty easily. I didn’t jab it with the thermometer, and the bag wasn’t under any kind of stress when I poked the hole. It’s possible that, if a grain caught it the right way, that the same thing could happen.
  • Pricey. They really aren’t that much money, but compared to a bazooka screen or a stainless steel mesh? This thing is a little expensive.

Bottom Line

The Brew Bag is an awesome product. It is well made, seems to be sturdy when it comes to grain, and delivers on its promises. I would absolutely recommend it to someone who is just getting into all-grain, or anyone looking to build a new mash tun. I see myself using this until it wears out (if ever), and even then I’ll probably buy a new one. Only time I don’t think I would be using it is if I ended up going electric. Rex, this product is amazing, way to go!

Couldn’t recommend this product more if you’re in the market to BIAB or Mash In a Bag. Check out the Brew Bag at the website, and show Rex some love for being a sponsor of the Reddit Homebrewing Competition!

Cheers!

Matt

The Big Wood Toasting Post

When I first started looking into using wood in my homebrew, my first question was “what sort of toast should I be using?” At the time I wasn’t aware there were multiple types of Oak, my homebrew shop only carries American White Oak, and the only difference I could see was the color of the wood. I had it (vaguely) explained to me that different flavors would come from the different “colors” (toasts), but that it didn’t matter too much which one I used.

I’ve come to really appreciate wood aged beers and the spectrum of character that wood can provide. It has become a big part of my research, and in that research I’ve repeatedly come to the conclusion that the toast of wood absolutely matters. I’ve tested it. But if it matters, how? Why? And what toast should I choose?

Time to explore the wonderful world of toasting wood!

How is wood toasted?

Barrel being toasted. Image from http://www.wineanorak.com/howoakbarrelsaremade.htm

Barrels are constructed in a cooperage by taking staves (the individual length of oak), setting them in a ring, and bending them into shape, then setting that shape with more rings. By heating the staves, they become more pliable and it is easier to bend them into the shape of the barrel. Some cooperage’s use steam to heat the barrels, but traditionally a flame is used and a very light toast can be imparted.

The actual toasting process is a different step. Once the barrel is shaped and set in place, the toast is applied per the needs of the specific barrel. The shaped barrel is set over a flame, and the intensity and duration of this flame is determined by the needed level of toast.

In homebrewing, we have some other additions available to us that follow a similar but not quite identical path.

Cubes are often toasted as staves, and then cubed. This results in a cube that has a noticeable red layer (the toast depth) on one side, while the other sides are lighter. Occasionally, staves are first cubed then toasted over a fire so that the toast is even on the outside of the cube.

Chips are almost universally chipped first and then toasted so that the toast is even on the surface area. The reason for this wasn’t made explicit, but if I had to make a guess it would be that because chips impart their flavors so rapidly, and that flavor is so one dimensional, it makes more sense to keep the toast consistent.

Spirals are fashioned from oak, though not necessarily from staves. They are designed to be an easier way to oak age, a single unit with an increased surface area (the spirals). Like chips, they are toasted as a whole unit.

There are other sorts of additions as well, but the idea is the same. The wood is either toasted before being shaped (cubes) or after (barrels, chips, spirals).

What happens during toasting?

During toasting, we are primarily concerned with three compounds in the wood: Cellulose, Hemicellulose, and Lignin. When wood is toasted, the bonds that compose these compounds break down and these simple parts change the characteristics that can be imparted from the barrel in different ways:

Cellulose is a natural polymer, the most abundant one on Earth, and is composed of linear chains of glucose. Its primary use is holding the wood together, and it doesn’t have a particularly large role in producing flavors.

Hemicellulose, along with cellulose, is found in the cell wall of plants and consists of short chains of sugars. Those sugars, when heated, are capable of caramelizing and producing a wide variety of flavors, including almond, walnut, caramel, maple, licorice, and the “toasty” flavors/aromas.

Lignins, also part of the cell wall, are vital in conducting water, and are composed of monolignols. When heated they break down and are responsible for producing the vanilla flavors and the smoky, clove, and floral aromas.

At varying toast levels and temperatures, these compounds release different characteristics, each appropriate in different circumstances.

Another bonus of toasting is that it mitigates the tannic quality of raw wood. Tannins can lead to some beneficial mouthfeel, but they can also impart an astringent quality to your beer. In raw wood, the surplus of tannins can lead to off-flavor-like qualities very quickly, much faster than the other compounds that you may want from the wood. Toasting breaks down tannins, lowering the amount that will end up in your beer or wine to more desirable levels.

There are other reactions that occur with toasting as well. Obviously, the color of the wood changes, as does the texture of the wood (though no nearly on the scale of charring).

What are the different toasts of wood?

Image from https://www.infusionspiral.com/infusion-spiral-systems/rhone-blend-barrel-pack.html

Typically, the toasts of wood are divided into three categories: Light, Medium, and Heavy. These toasts are created by toasting the wood for more or less time with more or less heat, and the shift in the levels of broken down compounds results in different characteristics from the barrel to its contents.

Light toasts

Typically toasted at a low temperature for a longer period of time. This breaks down tannins and hemicellulose, and facilitates the formation of vanillin, the chemical compound from lignin that is responsible for the vanilla flavors and aroma.

Since the wood is closer to raw than the other toasts, more mild, fresh wood characteristics are contributed to the aroma and flavor with this toast. The lower temperatures also result in more tannins being present, and more tannic qualities (including increased mouthfeel, when controlled) are found.

Light vanilla flavors are present, but due to the lack of heat lignin isn’t broken down too much, which means the vanilla is a bit restrained, but also means that smokey flavors aren’t created.

When should I use a light toast: Use a light toast when you are looking for woody, earthy, restrained vanilla characteristics. Personally, I use light oak when I am making beers like a lighter Old Ale, where I want the restrained character from the wood to be detectable but not dominating, and for the tannins to contribute to mouthfeel. Also appropriate in styles like Flanders Red if you want a lighter vanilla character.

Medium toasts

Toasted at a moderate temperature for a long period of time, which avoids harshly charring the wood and focuses primarily on the breakdown of hemicellulose, resulting in the carmelization of sugars.

Because of the medium heat, lignins are broken down a bit more and vanilla characteristics are much more prevalent at this toast than at lighter toasts. The additional heat also results in less tannins.

Due to the breakdown of hemicellulose and the carmelization of some of those sugars, medium toasts can contribute toasty, caramel, and maple flavors, as well as a well-rounded wood characteristics that is less “raw” than the wood characteristic of lighter toasts.

When should I use a medium toast: If you’re looking for the contribution of the wood to be a bit more obvious, you’ll want at least a medium toast. At this point, the balanced and multi-layered contribution of the wood becomes an aspect of the beer that is harder to ignore than the more one-dimensional contributions of a lighter toast. I use a medium toast for all of my wood-aged beers, except for the darkest like Russian Imperial Stouts. Oud Bruin, Old Ale, Flanders Red, Wee Heavy, any beer that you want to wood age and add some balanced complexity to is calling, in my opinion, for some medium toast wood.

Heavy toasts

Often the result of a two-step process. First, the wood is heated briefly at a high temperature, resulting in a strong surface toast that will impart smoky flavors. After that, there is often a medium toast for a slightly longer period of time which creates a red layer, penetrating the wood more fully and allowing for more complex flavors to develop.

Some vanilla flavors may be present but at this point the compounds in the wood have largely been broken down and the flavor and aroma are typically dominated by smoky, roasty, coffee like flavors balanced with notes similar to those present in a medium toast.

When should I use a heavy toast: I only use a heavy toast when I’m going bold. Big Oud Bruins, Russian Imperial Stouts, something that will benefit from those heavy characters from the wood. If you’re looking for heavy roasted characters with a coffee, almond, smoke like background, heavy toast is the way to go.

Temperatures of toasts and compounds

Different woods contain varying levels of the compounds we have talked about, and so there isn’t a hard-fast rule for “how much heat and time produces what compounds”. Even if the type of wood didn’t matter, other factors such as humidity, climate, and age of the wood also affect how the barrel is toasted. Below is a chart of roughly at what temperatures different characteristics are formed in American Oak, but keep in mind that this chart, while a good starting point and rule of thumb, isn’t universal.

You’ll notice that, as the temperature increases, lignin, tannins, and other compounds are broken down, resulting in an increase of vanilla and sweet qualities while rapidly diminishing the raw oak character. Towards the middle of the chart, right in line with a medium toast, vanilla flavors are at their peak and toasty flavors begin to develop as well. Finally, we end with those acrid, roasty, and almond-like qualities.

You said toast matters?

I did, I did say that. I also said I tested it. The toast of wood making a difference is one of those things that seems obvious. Of course a light toast will be different than a heavy toast, vinters and distillers have known this for years. Thanks to folks like Drew Beechum and Denny Conn (authors of Experimental Homebrewing) and the people behind blogs like Brulosophy, it has become something of a trend in homebrewing to test the status quo and challenge conventional wisdom. I’m all for this, not because I think everything we know about homebrewing is wrong, but because nothing should be beyond question.

Since the guy at the LHBS is convinced that the toast doesn’t make much of a difference, I decided I needed to test it. And involve him. And rub his nose in it.

For this experiment I decided on using my American Stout, primarily because I know it tastes good wood-aged and I really feel like having some stouts around.

Recipe Details

Batch Size Boil Time IBU SRM Est. OG Est. FG ABV
5.5 gal 120 min 70 IBUs 52 SRM 1.060 SG 1.018 SG 5.5 %

Style Details

Name Cat. OG Range FG Range IBU SRM Carb ABV
American Stout 13 E 1.05 – 1.075 1.010 – 1.022 35 – 75 30 – 40 1.8 – 2.5 5 – 7 %

Fermentables

Name Amount %
Pale Malt, Maris Otter 9 lbs 70
Chocolate Malt 1.1 lbs 8.5
Flaked Oats 1 lbs 8
Crisp Roasted Barley 0.65 lbs 5
Caramel/Crystal Malt – 60L 0.55 lbs 4.25
Caramel/Crystal Malt -120L 0.55 lbs 4.25

Hops

Name Amount Time Use Form Alpha %
Cascade 2.5 oz 60 min Boil Pellet 6.4
Cascade 1.1 oz 15 min Boil Pellet 6.4

Yeast

Name Lab Attenuation Temperature
Scottish Ale Yeast (1728) Wyeast Labs 70% 55°F – 75°F

I treated my RO water to the Dark Malty profile in Bru’n Water, and hit a beautiful mash temp of 152F. In hindsight, this is a little low and next time around I’ll probably aim for 154F.

bbiSJGp

I love the smell of a two hour boil. All of my stouts get boiled for a long time, I have absolutely nothing to back that up with.

And here they are fermenting away! I racked into a bottling bucket before splitting them into the fermenters to make sure the gravity was even (measured and just missed OG at 1.059). After two weeks in the fermenter (lost track of time!) with Scottish Ale Yeast, I went ahead and added these great looking medium toast oak cubes to the batch (notice that they have a consistent toast, meaning they were cubed first then toasted) on the left, and some heavy toast oak cubes from the same company on the right. Both were boiled for 15 minutes prior to being added.

I let them sit for two months. This was about 1.5 ounces of oak cubes, so two months is the lower end of what I usually recommend, but I wanted a more subtle wood presence. Plus, if the beers are distinguishable, that’s even more of an argument for toast being important.

After bottling and letting the beer sit for another three weeks, I went to the homebrew shop in my parent’s town. The guy who had talked to me about oak cubes two years ago was, not surprisingly, not working. Regardless, I got 8 people to participate in a short triangle test, which (if I understand correctly) means I would need 6 people to correctly guess the odd beer out. Participants were given three glasses side-by-side, two with medium toast stout and one with heavy toast. I asked them to pick the odd beer out based on aroma and based on taste. Based on aroma, only 4 people correctly guessed the different beer. Based on taste, 7 people were able to distinguish the heavy toast beer as being different than the medium toast.

Literally every single participant said that there was something different in the aroma, but only four picked correctly. So in a big roasty stout, maybe the toast will contribute to aroma, but not enough to make a difference on toast alone. Personally, in my blind tasting, I couldn’t smell the difference between the two.

For taste though, the people who choose correctly noted that the heavy toast beer was a bit roastier and more acrid. Five of the participants said they perceived the medium toast beer as sweeter. I personally don’t think the medium toast beer tasted sweeter, and while there was statistical significance the beers were more similar than I’m comfortable with.  I was expecting more of a stark difference, but it wasn’t there.

That said, this isn’t hard science, and this wasn’t even tested rigorously. You could easily disqualify everything I’ve said, in fact, I encourage you to. Give this a shot for yourself! Worst case scenario, you have some awesome wood aged beer around and a reason to buy a certain toast in bulk. Best case scenario, you fine tune a beer to a specific toast! Its a win all around!

Toasting your own wood

I’ve written about this before for Homebrew Finds while Chris was doing some travelling, and it was also a popular section in the initial Wood Primer. Most local homebrew shops will have some kind of wood available, but it is almost always a type of oak. In the spirit of DIY, terroir, and finding the perfect ingredient for my specific brew, I went about testing different kinds of woods, and this meant toasting the wood myself.

The most readily available and diverse selection of food safe wood tends to be the wood chips used in toasting. Despite some of my reservations about wood chips, they can be used effectively and they are a good starting point for exploring a specific type of wood in your brew. If you can get a hold of cubes or spirals and want to toast them, this guide will still be a good rule of thumb but you’ll need to play with the timing a bit! As I explore more toasting options and times, I’ll update them here!

The “quick and dirty” step by step to toasting your own wood

  1. Determine the type of wood (I would stick to toasting chips for now, check out the wood primer for determining the appropriate wood to use) and temperature you want (use the chart above as a reference).
  2. Pre-heat the oven to your desired temperature.
  3. Cover a cookie sheet in aluminum foil and then evenly spread your wood additions across the sheet.
  4. Put the wood in the oven on the middle rack.
  5. Set your timer for an hour, check on the wood every fifteen minutes or so.
  6. Take the wood out of the oven after an hour, toast longer if desired. Note that if you want a light toast, it won’t take an hour. Use your judgement!
  7. Allow the wood to cool, and add it to your beer using your preferred method.

How I do it

Last year, the blog Homebrew Dad (now BrewUnited!) ran a short contest to give away some yeast cultivated from the famous Heady Topper. The contest was to submit a recipe that you would use the yeast in, and I wanted to make a cherry wood IPA. Cherry wood tends to have light vanilla, earthy, a little astringent, and something a bit like dried cherries. I thought this would go really well with the supposed stone fruit characteristics of Conan, and so I was really excited about giving it a shot.

I didn’t win the contest, but I was still excited about the recipe, and so in preparation for my post on Homebrew Finds I brewed it.

I bought Cherry smoking-wood chips from my local Walmart after calling the company and ensuring no chemicals were added to the wood. For this recipe, I wanted hints of vanilla while complimenting the naturally sweeter, earthy characteristics of the wood, and so using the chart above as a guideline I decided to toast at about 350° Fahrenheit. Since I’m using chips, the toasting process will be fairly quick and I set a timer for one hour, checking the chips every fifteen minutes.

First, I preheated the oven to my desired temperature, then covered a cookie sheet in aluminum foil. I then spread five ounces of Cherry wood evenly across the sheet. Pre-toasted, the wood looked like this:

 

I put the wood on the middle rack of the oven and set my timer for an hour. Less than five minutes in, the kitchen has a great wood smell which, by the thirty minute mark, developed a characteristic I can only describe as “harsh”.

After the hour was up, I had five ounces of medium-toast Cherry woodchips, which looked like this:

 

Now, I was going for a lighter toast. I wanted a bit more restrained vanilla, while still having a bit of that raw wood character, so an hour was absolutely too long. I boiled the chips and added them to secondary, and ended up enjoying the beer. It was a little astringent, but there was more of a vanilla/toasty character than I had wanted for the recipe. It ended up dominating the beer, but did give it a really nice color. Still think I would have preferred a lighter toast.

Conclusion

The toast is a big factor in determining what characters your beer will get from wood. It is also one of the things that makes wood so great, the spectrum of flavors and aromas it can provide is nothing short of impressive. Whether you believe the level of toast makes a difference in your beer or not, I’d encourage you to look into different toasts for your brews and trying them out for yourself!

I hope this helped explain toasting a bit, and I know researching it has been incredibly valuable for me. If you see an error, or just want to share your experience, feel free to let me know!

Cheers all!

Matt

Resources

http://homedistiller.org/aging/aging

http://www.homebrewfinds.com/2015/03/guest-post-toasting-your-own-wood-chips-by-matt-del-fiacco.html

http://seguinmoreaunapa.com/products/barrels/toast/

http://www.eckraus.com/blog/making-your-own-toasted-oak

http://www.researchgate.net/publication/259863455_Influence_of_toasting_technique_on_color_and_ellagitannins_of_oak_wood_in_barrel_making

http://beersmith.com/blog/2012/02/20/oak-in-your-beer-oak-chips-and-barrel-aging/

http://www.brewgeeks.com/toasted-oak-cubes.html

To Trub or Not to Trub: Replicating the Great Trub ExBEERiment

There’s myriad information out there that we, as brewers, tend to take as fact simply because it has always been fact. Things like “hot-side aeration is bad” and “pitching at a slightly lower temp produces a better beer”. I’ll be the first to admit that I’ve considered both of these things as hard fact, without really looking into them. Why wouldn’t I believe the masters? Those who have come before me and have already been perfecting this art? Circumstances change, processes change, and I’ve come to believe that testing these “facts” is important.

Enter Brülosophy (the two dots above the u are called an umlaut, they denote a front-rounded vowel. So think “brewlosophy”. Linguistics. They also happen to make a smiley-face. And they’re totally metal). This blog is run by Marshall, aka Brülosopher , and in addition to being an awesome guy he has been doing some fantastic work in testing the long-held beliefs of the brewing world.

One of his exBEERiments that I found particularly interesting was “The Great Trub ExBEERiment“, in which Marshall tested how trub (hop matter, hot-break, the junk you leave in the kettle after the boil) affects the final taste of beer. Before reading any more of this article, I recommend you read Marshall’s article. Marshall concluded that the beer fermented with trub was brighter, clearer, had more hop aroma, and had a sharper and crisper flavor. Non-trub was smoother, and participants were pretty split on which beer they preferred.

He recently repeated this exBEERiment with a Vienna Lager, and found that there was no statistical difference between a no-trub and trub batch, though were certainly differences in the fermentation.

This is really interesting data, and if nothing else it suggests that maybe it won’t ruin your beer if you happen to get some trub in the fermenter, but it could certainly change the perceptions of it. While his results may be accurate for a cream ale or Vienna Lager, fermented at those temperatures, for those particular yeasts, etc., it doesn’t say much about beer in general. At least, not yet.

Pretty often, I see people telling Marshall what he should and shouldn’t repeat in these exBEERiments, and that “one instance doesn’t conclude anything that can be generalized”. I don’t disagree with the spirit of these things, but do disagree that this falls on Marshall. In fact, it shouldn’t. If we want to generalize, then let’s commit. My purpose in this was to commit, to repeat the Trub vs. No-trub exbeeriment on my system, using my process, my recipe, and letting the trub remain the only variable. If my results are similar to Marshall’s, then this is another data point that can be used towards generalization: that on an entirely different system, for an entirely different recipe, done by an entirely different brewer, fermenting with trub in the fermenter had/didn’t have an effect. SCIENTIFIC RIGOR Y’ALL

Recipe

It’s no secret that Marshall loves lagers, and for this exbeeriment he originally used a cream ale, and the second time around used a Vienna Lager. Me? Give me something dark, roasty, and 8% alcohol. Like this Old Ale.

Recipe Details

Batch Size Boil Time IBU SRM Est. OG Est. FG ABV
6 gal 60 min 53.7 IBUs 23.8 SRM 1.089 SG 1.028 SG 8.1 %

Style Details

Name Cat. OG Range FG Range IBU SRM Carb ABV
Old Ale 19 A 1.06 – 1.09 1.015 – 1.022 30 – 60 10 – 22 1.8 – 2.5 6 – 9 %

Fermentables

Name Amount %
Pale Malt, Maris Otter 18 lbs 77.59
Munich Malt – 10L 2.4 lbs 10.34
Caramel/Crystal Malt – 60L 1.2 lbs 5.17
Special Roast 0.7 lbs 3.02
Pale Chocolate Malt 0.5 lbs 2.16
Caramel/Crystal Malt -120L 0.4 lbs 1.72

Hops

Name Amount Time Use Form Alpha %
Challenger 2.5 oz 60 min Boil Pellet 7.5
Challenger 1 oz 10 min Boil Pellet 7.5
Fuggles 1 oz 10 min Boil Pellet 4.5
Fuggles 1 oz 0 min Boil Pellet 4.5

Yeast

Name Lab Attenuation Temperature
London ESB Ale (1968) Wyeast Labs 69% 64°F – 72°F

Brew Day

I don’t have too many pictures of this part of the process, but everything was incredibly standard. I mashed in at 152°F and thank God for giant whisks! This thing was nothing but dough-balls and was almost too much for my mash tun, it was quite the bill. Amazingly, I only last one degree over the 60 minute mash.

I did my 60-minute boil, nailed my volumes, and hit my intended OG of 1.090. In the first fermenter went 3-gallons of crystal clear wort, and into the second I, quite literally, dumped liquid and trub, leaving a bit of liquid behind in the kettle to make up for the space the trub took up.

I oxygenated, pitched, and oxygenated again after 12 hours. Surprisingly, there was a huge difference in fermentation. I’m fairly positive (as positive as one can be in this situation) that I pitched the same amount of cells into each fermenter. No-trub had the first visible signs of fermentation, but trub had a more vigorous fermentation throughout.  This was my first time using 1968 London ESB, so I didn’t have experience to compare this with, but it seemed like both batches had a good fermentation overall.

Fermentation

Ten days in, after fermentation finally died down, here is what I was left with:

Want to guess which one is No-trub? While both have residue on the fermenter, Trub clearly tried to spit all of the trub back out of the airlock (this is how Ray Found phrased WLP007 to me, I thought it was appropriate). For those still unclear, No-trub is on the left, and Trub is on the right.

No-trub (Left) versus Trub (Right)

This is a better shot of what has settled, and you’ll see that Trub has significantly more matter at the bottom compared to No-trub.

 

Both of them hit 1.025, a bit lower than predicted which is just fine with me, I was a little worried about this being too sweet anyways.

Trub and Non-Trub were, of course, primed separately to 2.2 volumes of Co2 using table sugar dissolved in one cup of water. They were kept in a dark cabinet, together, which typically sits around 68F, and were given three weeks to condition.

Testing

It was pointed out to me by /u/Rayfound that, because I bottle condition, that it could be challenging to eliminate the variable of pouring. How it is poured, into what sort of glass, how much sediment is in the beer, all of these things could influence how the final beer is perceived. I’m a bit on the fence here, I’ll be honest. On one hand, I want to ensure the only variable is the Trub, since that is what is being tested here. From a scientific (if you can call this science) standpoint, it would make sense to eliminate as much as possible. That said, I’m more interested in general practice than anything else. In practice, I wouldn’t try to control the pouring variables. I’d leave sediment behind, sure, but I wouldn’t be meticulously detailed to ensure every taster had the same pour. If I control the pour, and trub makes a difference, great. But if I don’t control the pour and trub doesn’t make a difference, then I would call the results negative, because I don’t, in practice, control the pour.

I split this batch with wood, and so I have 8 “controls” of trub, and 8 of no trub, control meaning batches that were not racked onto wood or blended. Two of these belong to a competition, and two of them are going to be kept to test them against the various kinds of wood I used. So that leaves 6 of each. I was fortunate enough to have six people volunteer to do the tasting, and for this test I decided to control the pour as best I can. Since I didn’t pour each person a full glass, I had some left over and two more people volunteered. For these two people, I didn’t control the pouring at all. Not enough people to make a definitive claim, but could absolutely hint at something.

And, of course, in true Brulosophy fashion, I did a triangle test. Each person was presented with two examples of Trub and one example of Non-Trub. They were asked to describe the appearance, aroma, and flavor of the beers, and the differences (if any) between them. After that, they were asked to pick the odd-one-out.

Out of the original six tasters, four of them accurately picked out the odd beer, Non-Trub, and two concluded it was the same beer in all three glasses. It was a fairly divided spread, which I found surprising, and it was a statistical difference, which isn’t something that we have seen in Marshall’s tests Marhsall pointed out to me that to be a statistical difference, five tasters would have needed to identify the incorrect beer, so we are actually consistent with Marshall’s findings!

Of the four who picked out the Non-Trub:

  • No one thought that Trub and Non-Trub appeared to be any different.
  • No one thought that Trub and Non-Trub smelled any different.
  • Three of the testers thought that mouthfeel was exactly the same, and one thought they were very similar.
  • Three of four tasters noted that Trub had a lingering flavor quality, despite being cleaner in the middle of the sip. Three people said this. I find that pretty interesting, because the “clean” quality is consistent with Marshall’s findings, while the lingering quality is not at all.

Now, of the two who were served the beer without any kind of care for pour:

  • One of them accurately picked Non-Trub as the outlier.
  • Both said the beers were incredibly similar in taste, appearance, mouthfeel, and smell.
  • The one who picked Non-Trub as different said that to him the glass appeared to carbonate differently and that there seemed to be a bit more of an astringent character in the Non-Trub beer.

Of the five total individuals who picked No-Trub, four preferred No-Trub and one preferred Trub.

My Impressions: I had a friend serve me these beers side by side, and I honestly wanted there to be a big difference between them. Considering the fermentation difference that I had witnessed, I was so ready for these to be different. I wasn’t served these beers before the other tasters, so I had no idea what they were talking about, but I can see it. They are so similar, it’s astounding. Non-Trub is different, but when I was doing my own tasting, I didn’t guess correctly, even knowing Marshall’s results. Once I read the results from other tasters and learned which was which, I could taste the difference, but I chalk this up entirely to confirmation bias. I can’t even say which one I like better, because I originally perceived them as so similar. I’m excited to try them in a few months to see how they age, and if they age separately.

So, what does this mean? Beyond “having trub in the fermenter won’t ruin your beer”, not much. My results were fairly consistent with Marshall’s, but not dead on. The Trub beer had a linger flavor quality, no statistical difference, and more people preferring Non-Trub to Trub. Either way, I found these results really interesting and hope to use it as another data point to be used in this discussion!

Special thanks to Marshall for initially doing this exBEERiment (and let’s be honest, all the work he does to deliver these things) and the tasters who took part in this test!

Happy homebrewing!

Matt

Yeast Viability Over Time

When you buy a pack of liquid yeast, there are two things you should be aware of. One is how many cells are in the pack. For yeasts by WYeast and White Labs, that number is typically about 100 billion cells. For other manufacturers like Omega Yeast Labs, that number is roughly 150 billion. The second thing you should be aware of is the packaging date. The packaging date is important, because conventional knowledge tells us that yeast viability decreases by about 20%-25% a month. So, to calculate proper pitching rates or yeast-starter size, the date is needed to get an approximation of how much viable yeast is available.

Earlier this year, Brulosopher, of BRÜLOSOPHY, posted a short article on his yeast-harvesting method. Basically, the idea is to make a starter larger than you need and end up with roughly 80-100 billion cells in excess so that you can build a new starter from the yeast in the future. This method is cleaner and less time consuming than previous methods, which include washing the yeast from a previous batch and re-using that.

I started harvesting yeast using Brulosopher’s method a couple month ago, not for every batch but absolutely for those that use yeast I plan on using again, like Scottish Ale Yeast from WYeast or The Yeast Bay’s Vermont Ale Yeast. The problem is that yeast is only viable for so long, which is why the packaging date mentioned earlier is important. Now, everything pertaining to yeast cell counts is a gamble. 100 Billion cells is almost never actually 100 Billion cells, but can fit within a range. So, moving forward, we need to operate under the assumption that these numbers are general answers, and not specific case instances. We are also going to assume storage at refrigerator temperatures in liquid cultures.

Why Can’t I Store Yeast Forever?

Yeast is a living organism, and so it can’t just sit forever. As yeast sits, it slowly begins to consume its glucose reserves, weakening its internal structure and eventually resulting in the yeast’s cell walls rupturing, killing the yeast. This rupture is actually what is responsible for autolysis, a factor of off-flavors in beer.

So, if you can’t store yeast forever, how long can you store it?

Yeast Viability Over Time

As far as yeast viability over time goes, there are a few different answers as to the “shelf-life” of yeast. BeerSmith, popular brewing program, uses something like:

1 Month: 75%
2 Months: 59%
3 Months: 46.5%
4 Months: 35.5%

To elaborate, there is a non-linear 20% decrease in viability per month. That means that if you begin with 100 billion cells, then after a month you would have 80 billion cells. After two months, you would have 64 billion cells. So the 20% decrease is not from the initial cell count, but from the cell count at the beginning of the measuring period. This non-linear model is the same model that the blog Homebrew Dad uses in its yeast calculator.

So, obvious flaw, this model would result in always having some semblance of live cells, which isn’t the case. Eventually, all the yeast will be dead (things are getting dark here…). However, I’m not sold on the 20% decrease in viability. This is mainly for anecdotal reasons, but that’s enough for me to start looking.

What’s the Max Amount of Time I Can Store Liquid Yeast?.

Before doing my own research, I turned to people who certainly have more experience than me.

The first  point comes from Brian of Brouwerij-Chugach in his response to /u/UberG33k of Immaculate Brewery. /u/Uberg33k asked if anyone maintained a yeast bank, a collection of yeast to be cultured and used for future batches. Here is Brian’s response.

Basically, he gives some speculative timelines for storing yeast. His assumption for liquid yeast at refrigerator temperatures is one to two years (you absolutely need to use a step-starter to build it up at this point). I think this is a little optimistic, but Brian knows what he is talking about, and my doubt in the 20% numbers gives me enough of a reason to believe there is something to this.

Second point comes from some emails I received from The Yeast Bay and White Labs.

The Yeast BayIf you’re unfamiliar with The Yeast Bay, go ahead and check it out. There is some awesome work being done in making some less-available strains more accessible. Personally, I’ve only used Vermont Ale Yeast, supposedly cultured from the famous Conan yeast. I also plan on using either their Saison Blend or Wallonian Farmhouse Yeast in a Belgian Dark Strong/Imperial Dark Saison I’m planning. In my response, Nick (founder of The Yeast Bay) mentioned that there are a lot of factors that go into yeast viability over time, and that there isn’t a one-size-fits-all answer. Nick says to use a yeast calculator to determine viability, because these approximations are all we have.

White Labs also mentioned there were too many factors to accurately determine yeast viability, however they did mention something that was in line with what Brian said from earlier, that, even under poor conditions and a long period of time, a few cells can remain viable (in theory) to culture more yeast from.

So, what defined “poor conditions” from a time standpoint? Michael Nicholson and Brooke Pearson from Oxnard college seem to think two years. In their piece, Nicholson and Pearson explore yeast viability with old and new strains of dry yeast and liquid yeast. For our purposes, the most interesting parts of their findings are that:

A: If both are fresh, liquid yeast outperforms dry yeast until about 130˚F. Important, because this demonstrates liquid yeast’s vulnerability to temperature, which makes storage temperatures even more important.

B: Old (two years) liquid yeast failed to ferment at all.

So, glad we found a roof on this thing. But two years? That’s the high end of Brian’s estimate, and way beyond the 6 months that a 20% linear depreciation rate would give. So what do the actual numbers look like?

Yeast Viability Depreciation

Obviously, the answers above aren’t specific enough enough. They point to a longer storage period than 6 month, but not to the actual viability of yeast. But it gives me hope. Take a look at this experiment detailed on Beer Advocate. All credit to LeeryLeprechaun.

In this study, LeeryLeprechaun split a starter of WYeast 1056 and tested its viability using a hemocytometer and methylene blue. He got the following results:

Culture Age: 3 Days
Viability: 98%

Culture Age: 10 Days
Viability: 97.75%

Culture Age: 19 Days
Viability: 96.6%

Culture Age: 31 Days
Viability: 81%

Culture Age: 38 Days
Viability: 80%

LeeryLeprechaun decided to restart his tests after this and I haven’t seen any other results. However, his findings are consistent with the 20% depreciation rate, but absolutely blows WYeasts recommended storage time (max two weeks) and the “50% viable after two weeks” number out of the water.

This next article is from Woodland Brew. If you’re interested in the specific details of the article, please give it a read. It is an awesome article.

The 20% decrease equates to roughly a .7% decrease in viability a day. Steven, the author of Woodland Brew, tested seven different yeasts and found an average of .2% decrease in viability a day. This changes the 20% a month depreciation rate to about 6%. This is awesome information, particularly because Steven is clear that his samples are refrigerated and that is what we are interested in. Steven has also posted this on Reddit before, and honestly deserves some more credit for the post.

So, here we have a much smaller depreciation rate, which is fantastic. But should calculator’s change their conditions because of it? Personally, probably not. A 20% depreciation rate means there are less cells available, and so a larger starter (or more step starters) would be recommended, which won’t hurt anything and could result in more cells overall. This could possibly lead to over-pitching, but over-pitching can be a bit difficult to achieve on a homebrew scale.

Conclusion

The point of the findings here is that you can absolutely store yeast for longer than six months, and that 20% depreciation rate is bunk if you are storing yeast under good (not even optimal) conditions. The 20% that Jamil claims is a good rule of thumb, but I think there is sufficient evidence to claim that it isn’t a dead-on number. Maybe not even all that close.

Without a microscope, there isn’t much more I can do in terms of this, but I think there is enough here to warrant more tests. I am going to continue sending emails, hopefully someone with a background in yeast and chemistry finds it interesting and would be willing to conduct the tests. If so, I’ll keep you all updated.

Moral of the story? Your yeast is probably more viable than you think it is, so get that starter going!

So How Do I Store Yeast for a Long Time?

If you want to save some liquid yeast but don’t know when you’ll be able to use it, or if you want to start a small yeast bank, here is what you should do to store your yeast:

  1. Make sure you are storing your yeast in cold temperatures, the ideal temperature range is about 33˚F-38˚F¹. Never let the yeast freeze, try to keep it as cold as possible. I’d aim for 34˚F.
  2. Store it with the same wort you would use for your yeast starter, low OG (1.040)  and no hops.
  3. Store it in a sterile container.
  4. Store it with as little oxygen as possible.
  5. In storage, yeast can still produce Co2 for a while since most refrigerators aren’t cold enough to stop the yeast immediately (and you wouldn’t want ti to be that cold in this case). For this reason, you want to release Co2 from the container every now and then for the first day or so.
  6. Store in sterile plastic, in case the Co2 builds up. Plastic should be more resistant to the pressure. I personally use these test tubes.

Always make a starter, and if you are storing longer than six months I would recommend using a step-starter. Use a yeast calculator. Even though the 20% number is more than likely not accurate, it is a popular rule of thumb and can give you a general idea of how large a starter you should be using. Plus, if you have more viable cells than the calculator thinks, than that’s a bonus.

If you want to store yeast for longer than a year, or want to have a larger bank, you should look into storing yeast on a slant and freezing it.

Hope this was helpful for all of you, it definitely was for me!

Cheers!

Matt

Resources

http://www.beeradvocate.com/community/threads/yeast-in-storage-viability-and-vitality.149989/

http://byo.com/stories/issue/item/1487-the-latest-on-liquid-yeast

http://eurekabrewing.wordpress.com/2012/11/18/yeast-basics-check-yeast-viability/

http://www.fungimag.com/spring-2014-articles-02/V7I1%20LR%20101Yeast23-27pdf.pdf

http://www.reddit.com/r/Homebrewing/comments/26gt3b/yeast_viability_and_growth_a_summary/

http://www.whitelabs.com/content/yeast-storage-and-maintenance-0

http://www.woodlandbrew.com/2012/12/refrigeration-effects-on-yeast-viability.html

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