Friday, August 9, 2013

BKYeast C1 / C2 100% Brett Test Batch - Recipe and Tasting Notes

BKYeast C1 and C2

Brewery: Bear Flavored
100% Brett / Pale Wheat Ale
Brewed: 5.12.2013

Bottled On: 6.28.2013
ABV: 7.1%

I've said it before and I'll say it again: it's a fantastic time to be alive for fans of interesting beer. Hops are exploding the flavor wheel and changing our perceptions of what beer can taste like, and while yeast hasn't quite received the same level of attention, I think it's only a matter of time until the thousands of undiscovered Brettanomyces strains out there start blowing the minds of unsuspecting drinkers. Thankfully, there are ever-curious, ever-enterprising brewers like Dmitri of BKYeast, armed with a utility belt of sterilized empty vials and driven by the lure of the funk.

Dmitri is an all-around awesome dude who I've greatly enjoyed talking to about all-things beer, and who was kind enough to trade yeast strains with me. (Telling friends "I'm meeting up with a dude to trade yeast strains," will, I've learned, earn you a response along the lines of "That is the nerdiest thing I have ever heard.") In return for a few vials of Conan, I received all three of Dmitri's Cantillon Iris Brettanomyces isolates, which, needless to say, I was extremely excited about. While only a handful of people had brewed with these strains back at the time I acquired them, their reported descriptions sound quite different from anything else out there, particularly the "traditional" B / C / L Brett strains sold by White Labs and Wyeast.

After propping the three strains up, I planned a base recipe to be split between the three jugs, with some of the extra wort siphoned off and saved for starter wort. However, approaching brew day, I noticed that C3 didn't seem to be taking off like its two siblings, and a few days before brewing I decided to hold off on that one and brew with it at a later date. However, I still didn't quite play it safe enough, and a few miscalculations may have bled through into some mild off-flavors in the finished product. Nothing batch-ruining — I'm enjoying both beers, particularly C2 — but I'm sure I could have treated them a little more sensitively.

The weird measurements I ended up performing to split my mash between two 1-gallon beers and a few extra gallons of starter wort meant that my Original Gravity came out significantly higher than expected, somehow, around 1.068. I was aiming for around 1.055, and this meant that these wild Bretts — which had never previously fermented a full batch on their own, remember — were faced with a pretty strong batch to tackle. Nonetheless, I'm pretty confident that I still over-pitched, if anything — I estimate that I pitched around 200 billion cells into each 1 gallon jug of wort. As you can see in the picture below, the yeast starters were extremely active, actually more so than my usual Sacch starters. With both jugs quite full, I wasn't able to aerate much — mostly just the action of pouring the wort into the jug. However, Brett is generally comfortable fermenting with minimal aeration, and will usually produce less tartness as a result, so I wasn't too worried about aeration at the time.

Over-pitched or not, something I've never seen before happened: it took 6 days for a krausen to form, and the airlocks to start bubbling. Given how vigorous the starters performed (seriously, look how much krausen that guy is spewing), I was quite surprised by this. Both batches followed the same timeline, and finally began fermenting just as I was starting to really panic, then continued to ferment for another two or three weeks. Both finished around 1.013, which is a much higher FG than others who have used these strains saw. I hit just under 80% attenuation on both batches, while others have reported 95%+.

I'm not entirely sure what it was that held the fermentation back so much — do these yeast strains require lots more aeration than I gave them, do they not like hops, or do they simply have a mind of their own?

Appearance: very pale orange / light gold, decent clarity, minimal head
Smell: wild strawberry, musty forest, sweaty Brett funk, white wine, mead, oxidized note
Taste: tart tropic fruit, forest berries, hoppy mid-palate, mead, sweaty funk, slight medicinal,
oxidized note
Mouthfeel: light body, tart, dry, med-low carbonation, acidic finish

While it's clear that a few misjudgments in my process gave this some handicaps — notably an oxidized character that's prominent at first but fades after some minutes — the BKY C2 strain still manages to shine. Of note, beyond the characteristics mentioned above, there's something about this beer that conjures the character of a wet forest meadow full of ripe, musty fruit. It's a bit different from the typical "barnyard" character: "wild," but in a different sense, kind of sweaty, earthy, and over-ripe. I've also used "mead" as a flavor descriptor above — I'm not sure if you're allowed to use mead as an adjective, but a few people, including myself, have picked up on a fermented honey-like note in the background.

The most surprising aspect of this beer, to me, is not all the wild and funky flavors that emerge upon pouring — which are pretty much in line with what Dmitri described — but how tart it is; borderline acidic. Now, I have always gone out of my way to stress to people that 100% Brett beers don't conform to people's preconceived notions of "Brett beer." Brett does not make beer sour — acidic or tart, sure, but not truly sour — and as I've tried to make clear with most of these brews, a Brett primary doesn't even get very funky most times.

So having just explained that Brett doesn't really make sour beer, I must say that this batch came out shockingly tart, finishing with an undeniable, crisp acidity. It's tart beyond what I've gotten from other Brett strains in similar fermentations, and doubly surprising considering that this C2 test finished at 1.014 Final Gravity — I was worried there might be some clashing sweetness, but there's not, at all. I would never guess that this beer had such a high gravity by how it tastes. Even weirder, reports from other brewers suggest a much lower final gravity in their batches, down to the low single digits. Dmitri himself saw a test batch finish at 1.001, which is a huge difference. And which in turn leads me to a few conclusions for brewing with C2 in the future.

First, and most obviously, a drier beer with little residual sugar will enhance the perception of tartness or acidity. Brett generally creates a more acidic profile when aerated more (and might create a bit of acetic acid when given access to continued O2, such as in barrel aging), and conversely, ferments somewhat clean when not aerated (or not aerated much) to start off with. Obviously, though, this is strain dependent — there are like a million strains of Brett out there, and there is huge variation between them. But given my experience, at least, I would suggest to use C2 in beers where the profile allows for an enhanced perception of dryness, tartness and acidity. Not that many people are fermenting stouts or malty beers with Brett, but I definitely wouldn't recommend that here.

Appearance: very pale orange / light gold, decent clarity, minimal head
Smell: musty, woodsy funk, tart fruit, mango, tangerine, peach, slight citrus hops
Taste: tart tropic fruit, 
mango, tangerine, woodsy funk, slight acidity, slight medicinal, oxidized note
Mouthfeel: light body, tart, dry, low carbonation, slightly tannic / bitter finish

At least in my experiment, it seems vary apparent that C1 is from the same source as C2, and perhaps even that the two strains are "related". Both have the same woodsy, dewy funk character, but the berry character is less pronounced in C1, and the off-flavors are a bit more noticeable. In particular, my C1 batch suffers a bit from a tannic, astringent finish that may be a result of tossing too many hops at a yeast-focused test batch. As with C2, there is a sort of "flat" oxidized character that I'm sure resulted from the 6 day fermentation lag, but is at least more of a lingering distraction than an aggressive flaw.

This too is still a very enjoyable beer: tart, woodsy, and funky in a very unique way from what one expects of other Brett strains. It is very clear that these two strains share a common lineage, and indeed, there is maybe like 90% overlap between their flavor profiles, with C2 leaning more towards rounded, dewy berry notes, and C1 expressing itself with some hints of tangy citrus fruit like mango, tangerine and apricot. These are hard profiles to describe, honestly — the kind of totally new flavor profile that you simply have to experience before you can start applying associations to it.

While the oxidized character bothers me, my C1 improves drastically as its allowed to open up. The astringent finish fades as the beer the more the beer sits, and is replaced by a pleasant dry tartness. Like C2, I think this yeast has a lot of potential, though I'm wondering if the overlap between them may cause me to simply pick a favorite and continue with that. With both strains, a pale, yeast-focused recipe with a simple grain bill and low-IBU hop bill seems to be the way to go. Perhaps a cleaner fermentation will allow the yeast to play better with hops — so far I've been thinking that a "pale wheat ale" type recipe is the best fit for 100% Brett beers. In a few months, I will finally get to brewing with C3, and will give C2 a second go-around in a recipe catered more specifically to its unique strengths.

2 Gal., All Grain
Brewhouse Efficiency: 75%
Mashed at 151 F for 65 minutes
Fermented at 72 degrees F
OG: 1.068
FG: 1.013
ABV: 7.1%

71.4% 2-row malt
22.9% white wheat malt
2.9% Biscuit
2.9% Aromatic

Hop Schedule-
0.25 oz Columbus @60
1.75 oz Columbus @5
1.5 oz Simcoe @5

BKYeast C1 / BKYeast C2


  1. I'm surprised if you got an oxidized beer from the lag time. I've just never heard of that, but I guess it could be possible.

    Nice description of each strain. I have all three strains in wort from last year that I should bottle up and try. Thanks for the reminder.

    1. Yeah, I don't know... I don't know what else to call it. It's not "cardboard" in any way, but there's a kind of "flat" feel to it. I guess it's more likely just a general fermentation off-flavor that I don't have a proper word for. These strain's way of showing stress.

      If we're able to meet up in San Diego, I'll try to bring some along.

  2. Yup, sounds about right. I've experienced the same thing. As I said before - go easy on the hops, because C1 especially makes them shine through. That's the reason for that astringent dry hop taste.
    In any case, it's still too young. Mine weren't even bottled until over 3 months after brewing. They drop to around 1.012 in 3-4 weeks and then slowly go down to ~1.001 over the period of the next 2 or so months. Taste them in 6 months and you'll see how much they mellowed and smoothed out.

    1. Hmm, hopefully they don't continue dropping down to 1.001! I will have some exploding bottles on hand if that's the case. They were stable in the carboy for a while, and they've been bottled for about a month with no chance in carbonation. So far it looks like they might just be finished. I do plan on drinking them slowly to see how they develop, so I will have to keep an eye out for any chances in carbonation.

  3. Your results for C2 sound surprisingly similar to the results that I experienced with C2. I'm pretty sure all of the acidity that I experienced came from the yeast, but there was enough to make me think it could have been bacterial. But your descriptions seem very close to what I experienced.

    1. Hmm, good to hear my batch wasn't totally out there! For the first few days I was worried about some sort of infection taking hold because of the fermentation lag, but I'm 99% sure nothing else got in there. All C2 yeast character, I think.

      Out of curiosity, how much did you aerate and pitch, and did you experience any sort of lag?

    2. Here is my write up

      I guess you could say there was a lag phase. Initially a pellicle formed then CO2 was trapped in the pellicle. Then the pellicle dropped out and there was thin layer of krausen, followed by a pellicle again. It was one of the stranger fermentations I've seen. I've only had one other Brett beer form a pellicle and that was post primary fermentation and after I dry hopped it.

      I shook the carboy like I normally do but I think the big key to my aeration comes from the way I chill my wort. I have to pump it through a jockey box and it creates a lot of aeration when it pours into the carboy.

    3. Very interesting, for sure. I don't think mine ever formed a pellicle, during fermentation... I think after a few weeks there was a thin pellicle, but I can't even say for sure.

      It's sounding like everyone that brewed with this yeast didn't aerate it, which is interesting. I'm wondering what would happen if you aerated this quite a lot. Something I'll have to find out when I brew with it next, which probably will be in a few months.

      Checking out your blog, it looks like you're doing some cool stuff. It's always awesome to be able to read about similar projects from fellow brewers.

  4. Great post. I am really excited to jump forward 2 months and taste my C2 Blonde. I really like reading these posts on Brett and how it changes between the different brewers. It seems like aeration is a big deciding factor on the yeast so far. I have little to no hot side aeration on my beers. I also was very careful to NOT aerate the wort at pitching time. I get no funk at all, granted it is only a week old and still at 1.020. It is now off temp control (of 64) so I have a feeling the beer will funk up a bit as it starts to stress down to the last bit of fermentation.

    1. Yeah, aeration definitely seems to be a big variable with this strain. It's really cool seeing how different (but consistent in some ways) the results between brewers are. If only it were easier to meet up with everyone brewing these and taste them all!


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