Frankenstout is beer born of a lab experiment.
White Labs Brewing Co. is bottling beer for the first time, releasing its Frankenstout March 17 at its Miramar tasting room. The brewing arm of the yeast cultivator made the unusual take on a stout with a mix of 96 yeast strains. Most beers are made using one or two.
"It was like one big science experiment," says White Labs senior research scientist Karen Fortmann. The concept was born of an actual science experiment — White Labs provided the 96 strains to local biotech firms Illumina and Synthetic Genomics to map their genetic sequences. "We had all these yeast strains propped up and ready to go for sequencing," adds Fortmann. "Since we had a bunch of this already made, we figured we might as well put them all together and stick them in a beer to see what happens."
What happened is the yeasts competed for dominance. During the brewing process, yeast feeds on malted grain sugar, producing alcohol, each strain contributing different-flavored compounds to a finished product. With 96 yeasts consuming the same sugars, some strains reproduced at a faster rate, growing their populations in proportion to others. When it first made Frankenstout in 2013, White Labs used the same population of yeasts through 12 different generations — and each of the 12 ensuing batches of beer resulted in different yeast profiles.
"By the end it was a full-on clove phenol bomb," recalls Fortmann. "The Belgian yeast definitely won out." Similar to selective breeding of animals, she says, brewers yeast strains have been domesticated over centuries. Most don't produce the phenolic, clove-like compounds Belgian yeasts are known for. But Belgian palates selected for these flavors, meaning they're slightly less domesticated. "It's kind of like a wolf or a dog," she suggests, "who's going to win the fight? It's probably going to be the wolf."
White Labs actually keeps more than 500 strains in its bank, including some of what brewers typically refer to as a "wild" yeast, Brettanomyces. However, the 96 used in this sampling included more domesticated strains of saccharomyces cerevisiae and pastorianus — in brewers jargon: ale, lager, and hefeweizen yeasts.
White Labs brewer Joe Kurowski says managing these competing life forms meant adjusting the brew process to keep the yeast from completely thinning out the beer. "We're actually trying to prevent the yeast from drying it out," he says. "They're all good at eating different sugars — it's actually a struggle to keep some body in the beer."
Going into 750-ml bottles this year is a second-generation batch of Frankenstout, less of a "clove bomb" than that 12th — though even the results of a third generation would be unpredictable. Kurowski describes the experience of drinking it: "The first sip, it's always very woody, it's got some cedar notes…as you keep drinking it some more complexity comes through, you get some chocolate, roasty flavors, a little bit of vanilla, some banana. It kind of morphs as you drink it."