“If a plant or microbe can do it, we can engineer a yeast to do it,” says Charles Denby, cofounder and CEO of Berkeley Yeast in Oakland, California.
Using a gene-editing technology called homologous recombination—essentially hacking DNA’s natural repair mechanism to insert or remove gene “cassettes”—Berkeley bioengineers yeast strains to do things that are beneficial to brewers.
So far, Berkeley has bioengineered various yeast strains that can:
- liberate free thiols
- keep diacetyl below flavor thresholds
- produce lactic acid
- produce terpenes during fermentation
- remove their diastatic properties
While Berkeley makes strains with these properties commercially available, the lab also can bioengineer a custom yeast strain for any brewery. Similarly—to name a handful of examples—Lallemand Brewing markets Sourvisiae (a lactic acid–producing strain), while Omega Yeast markets two thiol-freeing strains (Star Party and Cosmic Punch), plus two strains with phenolic-positive traits removed (Bananza and Sundew).
While relatively new, bioengineered yeast strains already are changing the way breweries think about and make beer.