The Four Species of Brettanomyces

Currently, there are four species of Brettanomyces that are recognized by science. With the various mutations that exist of these species, it’s quite a task to nail down precisely what each will do when introduced into a beer, but I’m going to try to do just that.

As a reminder, the four species are: B. anomalus (also called B. claussenii), B. bruxellensis (also called B. lambicus), B. custerianus, and B. naardenensis. (To quell this right now: the yeast formerly known as B. nanus has since been reclassified as Eeniella nana, much like The Artist Formerly Known as Prince has been reclassified as that funky symbol. So, in short, it’s not Brettanomyces.) As noted in an earlier post, the two species that are most common in brewing today are B. anomalus and B. bruxellensis, but some have begun to experiment with the latter two, as well.

First, lets answer the question that’s been nagging you (or at least, nagging me): Why do B. bruxellensis and B. anomalus have aliases? According to Chad Yakobson of Crooked Stave (who literally wrote a dissertation about Brettanomyces and its viability as a primary fermenter), it’s old nomenclature, and geneticists have since looked harder at the DNA of each species and determined they’re not so different after all.

Of course, that begs the question, “Then why does White Labs sell both a B. bruxellensis (WLP650) and B. lambicus (WLP653)?” That’s where it gets more complicated, and why the above statement, about this entire venture being foolhardy, comes more into play. These two yeasts, which are the same genetically, still produce different results in the beer. Introduce Wyeast’s two versions (5112 and 5526) and realize that these, too, will produce even further different results.

To make sense of this, consider Saccharomyces cerevisiae: it is the general species of “brewer’s yeast.” It encompasses every type of that yeast, from the Saison DuPont strain to the West Coast Ale strain, all of which have different impacts on a beer’s flavor. Yet they’re all the same species, genetically speaking.

Another example: my wife and I are of the same species. Yet we are different in very distinct (and pretty obvious) ways. I’m the bruxellensis to her lambicus. Get it?

With all of that out of the way, how about we look at some of the flavor profiles that can be produced when using these various species of Brettanomyces and just really muddy the waters a little further, huh? (Conveniently enough, you can find a table that makes much more sense of all this compiled by Levi Funk of Funk Factory, which he has compiled with help from Brandon Jones at Embrace the Funk, and Al Buck from East Coast Yeast.)

B. bruxellensis

Like mentioned in the post pertaining specifically to B. bruxellensis, this species is known primarily for producing the “barnyard,” “horse blanket,” and generally funky flavor profiles when used in secondary, and much fruitier notes when used as a primary yeast. It’s worth noting again that the Wyeast and White Labs variants are seemingly different, producing different (albeit similar) flavor profiles. Wyeast claims “sweaty horse blanket,” while White Labs only claims “medium intensity” character. Like mentioned before, Central State’s house yeast is a mutation of B. bruxellensis, which can provide fruit, peppery notes, funk, or a completely clean beer depending on its use (primary versus secondary, fermentation temperature, etc.).

However: Wyeast’s B. lambicus boasts a distinct cherry flavor in addition to the traditional Brett funk, and White Labs’ Lambicus has “high intensity” character, being “horsey, smoky, and spicy.” The differences in all of these strains, even though they’re the same biologically, goes to show the distinct differences you can have between the same species, akin to the differences in vastly different Saccharomyces cerevisiae.

B. anomalus

The B. anomalus strains tend to be big producers of esters. Some strains produce leathery notes, while others provide fruit forward flavors, pineapple specifically (from B. claussenii-named strains). Wyeast no longer produces their anomalus, but White Labs’ claussenii is their low-level character-producing Brett. Depending on their use in primary or secondary, you may get some mild funk, and maybe even a bit of acidity.

B. custerianus

As far as my research shows, there aren’t many (if any?) commercially available strains of B. custerianus. The last available was from East Coast Yeast, and it seems to have last been produced in 2013. Michael Tonsmeire (aka The Mad Fermentationist) is the only account I can find of having used this species. He claims when used in primary that the yeast is “lager-like” when young and fruitiness emerges when aged. In secondary, it’s the opposite: fruity when young, becoming much cleaner as it ages.

B. naardenensis

There also aren’t many species of B. naardenensis available commercially, either. The one that may be most well known is from East Coast Yeast, and that particular version is known to produce some intriguing flavors, including ripe fruit, honey, and some acidity after six months or so of aging. However, Tonsmeire has also noted that the finish might taste “goaty,” which…well, whatever floats your boat, I guess.

We can hope that as more breweries focus on Brettanomyces fermentation, we’ll see more commercial examples of what these species are capable of producing. And like Tonsmeire notes in his book American Sour Beers, there may be species floating around in the air all around us, just waiting to be captured and examined and tossed into wort.