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Bell’s Beer Science: Yeast, the work we don't see that makes beer

Yeast workhorse of the brewery

Yeast are the workers we don't really see make beer here at Bell’s. Our brewers work hard on recipes and maintaining quality, but what we humans do is essentially brew complex sugar water (or wort) — it’s the yeast cells that eat the sugar and create alcohol and carbon dioxide, along with an array of flavorful esters. Because of this, we must carefully monitor our yeast to help ensure the beer you enjoy is the quality you expect. 

Most of our beers use the same proprietary house ale yeast. It’s the same yeast that help us brew a variety of styles and flavors - everything from Oarsman Ale to Expedition Stout.  Working together with our carefully-selected malt and hops, that yeast creates a particular ester profile during fermentation that makes our beers unique.

We primarily use three types of yeast here at Bell’s: our house ale yeast, a Belgian yeast strain (both Saccharomyces cerevisiae) and a lager yeast strain (Saccharomyces pastorianus) Saccharomyces yeasts are special because they produces CO2 and ethanol from sugar. 

Yeast health and performance are of the highest importance at Bell’s. Yeast are very good at fermenting sugar to alcohol and CO2, but when used over and over again it shows a predictable decline in vitality.  Because of this, we need to start with a fresh culture after a set amount of fermentation cycles.  In our laboratory, we have a cryogenic freezer where we store our yeast. Cryopreservation has been a popular topic in pop culture like the movie Austin Powers, and some people even have their cells cryopreserved in hopes of future revival.  Scientists do not currently have this technology, but there is quite a bit of excitement of the potential uses for humans.  The freezer is set at -80C (-112F), and we use special freezing media with glycerol when depositing the samples in the freezer.  Cryopreservation effectively puts the yeast in a state of suspended animation and greatly reduces the chance  for spontaneous mutation.

That’s an overview of how yeast works here at Bell’s. Check back often for more insights from our Quality Lab team.