The Secret Life of Yeast

By Ken Weaver Published March 2012, Volume 33, Number 1

The Next Generations

If one could conceivably graph the overall diversity of yeast populations that the average brewer uses as we progress forward through history, it would presumably start taking a nosedive around the end of the 19th century, with perhaps a slight uptick in recent years. The ability to isolate and cryogenically maintain—“domesticate,” in a sense—yeast strains has dramatically slowed their genetic shifts, and this can ultimately be interpreted as a reflection of the commercial realities of our current beer cultures.

Even at our most puristic, we still perceive value in a beer brewed consistently batch after batch.

Speaking about Dogfish Head’s line of Ancient Ales, Calagione said, “one of the liberties that we’ve taken with a lot of these [beers] is we’re going with a single strain of yeast, where, in reality, beers thousands of years ago were almost definitely way more akin to what a lambic would be today.”

There’s been a quiet tradeoff there, and we’re at a point in time where the majority of our commercial beer is brewed with a single strain yielding generally consistent results. In a section of Farmhouse Ales, Yvan De Baets cites a 1920 passage from a beer writer named Marc H. Van Laer, who wrote, “It seems, for example, that if the application of the pure cultures method has improved the average quality of the beer, if it has decreased the chances of infection, it has given us beer with less character than before.”

De Baets goes on to add, with a straightforwardness that’s pretty refreshing, that “the current situation of Belgian beer, some having become caricatures of themselves with their mainstream, standardized flavors, shows us that, unfortunately, Van Laer’s warning was not heeded.” While the historical context of De Baets’ commentary limits it from having quite the same resonance for a predominantly American audience without that same farmhouse brewing culture to fondly look back upon, it still raises an interesting point.

Truckloads of different hops. Pallets of specialty malts and adjuncts. One type of yeast?

White Labs and other brewing laboratories offer a number of blended yeast strains (which are generally produced as pure-culture individual strains that are then blended to the appropriate proportions before shipment). Chris White commented, “It’s a fun way for people to diversify their beers even more.” When asked whether breweries were requesting and using the blended strains more frequently, he answered, “it’s on the rise, for sure.” There have been smaller yeast companies popping up recently, such as East Coast Yeast in New Jersey, which specializes in complex blends with names like “BugFarm” and “Saison Brasserie blend.”

Whether these small pieces accurately forecast any larger movements towards greater experimentation and overall complexity in how American craft brewers obtain and utilize different yeast strains remains to be seen. Then again… craft brewers are usually looking for that next envelope to push, and this one seems to be a relatively uncharted landscape right now. It’s implausible that the ways we use yeast will ever return to their pre-19th century status. But occasionally grappling with yeast’s diversity and wildness seems to be an appropriate way to appreciate what they once were in beer’s history, as well as what they can still be today.

Ken Weaver is a beer writer, fiction writer, and technical editor based in Santa Rosa, CA. His first book, The Northern California Craft Beer Guide with photographer Anneliese Schmidt, will be published by Cameron + Company in Spring 2012.
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  1. 1

    Great article!

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