Where's the Brett?- WLP644 Brett Trois

Where's the Brett?- WLP644 Brett Trois

Where's the Brett?

Depending on your level of beer nerdiness, you may or may not know about the recent controversy surrounding White labs 664 Brettanoymces Trois. If you are not aware of it WLP644 is a newer strain of "Brettanomyces" renowned for it's fruity character as opposed to the more well known funky sweat and farmhouse basement. It has become increasingly popular as a go-to strain for 100% brettanomyces fermentations. In fact it is becoming synonomys with them as they become more and more popular amongst brewers, home and pro alike. A lot of that had to do with the fruitiness in the flavor and the way it ferments so much like normal yeast. Well there is a reason it ferments so much like normal brewers yeast. According to laboratory Omega Lab's tests WLP644 is not brettanomyces but sacchromyces, or regular brewer's yeast.

If you want a more in detailed look at the issue (complete with lots of science and what not) check out Embrace the Funk's in depth article here. It gives a timeline of the tests and documents who said what and what their reasons are.

Now I am interested in 100% brett fermentations. I think it's a unique and cool idea, and some of the ones I have tried were mind blowing. So I went ahead and bought myself a nice shiny tube of ole WLP644 Brettanoymces Trois. You can see that in my teaser video for a 100% brett pale ale here. I have great timing because about the second I poured the starter into my wort the genetic watergate broke online.

So what are my thoughts on WLP644, and maybe more importantly how is that beer? Well my beer is bottled and conditioned so lets get into my humble opinion on the matter. (it's going to be broken into a few arguments)

The Ferment

Well this yeast fermented pretty normal actually. From my research on the internet part of the old appeal of this strain was that it acted and fermented just like brewers yeast. (That's called foreshadowing folks) The yeast took off over night after pitching the starter. You can actually see a time-lapse of that fermentation start here. It had a normal kreusen and fermentation activity ceased in about 4-5 days.

Now here is where things I did not expect started happening. With a brett strain I expected high attenuation. Imagine my face when I saw 1.018 in the hydrometer after primary ferment had slowed down. Ok thats not all that nice for a beer that started at 1.048. I was not going for a thick table beer here. So I needed to get that gravity down. I had read that sometimes 100% brett fermentations can stall out and need some time to shave off those final few points. So I roused the yeast and increased the heat and gave it two more weeks.

In the end impatience won out and I bottled that sucker at 1.015, having lost only 3 gravity points. By this time the story had broken online and I was both pissed and curious, so I put it in bottles. I even added priming sugar, bottle bombs be damned. I put my life on the line to test if there was brett (because my wife would kill me if a case of beer exploded in our house).

The Taste

Skipping the appearance for now (hint:it looks like beer) we are more interested in the taste and smell. I didn't dry hop this beer because I wanted a feeling for how the yeast tastes. Right off the top the smell is pretty unique. A sort of bright wine like slightly acidic note. When it was very very young it was like a champagne note, now it has dimmed down to a slightly mustier and earthy smell with some vinous background. It does remind me of brett and I would certainly believe it could be made by a strain with low characteristic brett flavors.

The flavor is also very unique. There is a grape juice type flavor here. A vinous flavor that again used to be a bit brighter. There are also subtle hints of a very brett like flavor, that I personally find off putting in brett beers. You may know it as this slight rubbery taste, not particularly harsh but present. It is in this beer in the aftertaste but very very faint. Other flavors I would associate are a bit of earthy spice and a very low peppery character, almost a saison type quality. There is a bit of acidity almost too it as well.

These flavorings are confusing in that they could very well be created by a mellow brett strain. Again though I have had these same flavors in some clean saisons too. In fact when blind testing several people with this beer they have mentioned thinking it was a very full bodied saison. Lets talk about the body. It's slick and full, you can really feel that high finishing gravity. It would be a much better beer if not for the high gravity mouthfeel. The carbonation is very soft, slightly undercarbed. The yeast character does a decent job of distracting from that full body but it just doesn't fit well in this type of beer and really says something about the yeast not being able to get through that sugar.


The beer first sat in my office at normal room temperature for 3 weeks while it was "carbonating", then it was sent out of my site into the cold storage area of our house. I have been drinking bottles each week to test carbonation levels and out of concern for explosions. Well the stuff is over 6 weeks in a bottle and is actually undercarbonated (as mentioned earlier). On the one hand it's nice to not open gushers or have my storage full of exploded beer, on the other hand it does not bode well for this yeast.

My Conclusion

I'll make my opinion clear right from the first sentence; there is no brett in WLP644. The nail that really seals the coffin in my eyes is the super low attenuation and the very low refermentation in the bottles. While the taste may be reminiscent of brett, I think the evidence does firmly point in the direction of a very unique sacchromyces strain. I have heard that some of the new saison strains from yeast labs like Yeast Bay can mimic funky brett flavors while still being completely clean sacc strains. I really think that's what is happening here as well. In my mind it's the only thing that explains the fermentation issues and lack of fermentation in the bottle. Brett is relatively aggressive, and anyone who has ever had an infected batch knows it usually means you will have to break out the towels when opening.

The biggest issue I take with this whole thing is that it is marketed as a brettanomyces strain, which means it is a more "premium" strain. That gives it a premium price tag (75 Kroner in Denmark) and a lower cell count (2-3 billion per vial as opposed to 60-100 in regular brewers yeast vials). So in the end White Lab's only real sin is not double and triple checking their source on this strain. Possibly even an honest mistake, but still disappointing.

Well that's my opinion. I'm no doctor, just an armchair beer scientist. I've brewed with it, noted my results and here they are. If you are a big microbe enthusiast and have a different opinion I would love to hear it. Maybe you had a different result with the strain. Leave me a comment here, on facebook, or on my youtube video below. Beer is a journey and this is but a bump in the road to perfect brews. Cheers!

Update: White Labs has confirmed with their research that this yeast does not contain brett. Read more on their site here.

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