Being an avid home brewer has granted me insights about the sensitivity of yeast cells to small fluctuations in the environment. Moreover, interaction with the ale industry has opened up some intriguing opportunities for the study of evolutionary biology.
Ale strains have been isolated from one another for decades (or sometimes centuries, e.g. Guinness’s yeast strain was isolated in the 1800’s). During that time, many of these strains have been evolving. The efforts of breweries to maintain similar properties from year to year have likely imposed strong stabilizing selection. We recently studied 36 unique yeast strains used in ale production to understand how stabilizing selection enriches for certain types of genetic interactions (see our article in PLOS Biology [click here]; and a primer article [click here]).
Currently brewing beer is just a hobby, but there is much *untapped* potential for future inquiry. For example, some breweries do not obtain fresh yeast from the freezer for many batches of beer and notice no change in flavor. Other breweries notice immediate inconsistency if they re-use yeast from one batch of beer to the next. Are these breweries repeatedly observing yeast evolution (and do the same adaptive mutants always win)? Very cool.