Google+

Blinded by Science: Increasing Ethanol Tolerance in Yeast

Leave a comment

November 20, 2015 by fhsteinbart


Yeast Tolerance

Here we see the data on increasing effects of ethanol on yeast populations with concurrent increases in mutative strains.

There was a great article published by the Leuven Institute for Beer Research in Belgium. Their basic research showed that there were heterogenic populations of yeast after several generations from increasing sugar content. This parallels my own observation of increasing the sugar content in my own worts to produce  stronger beers. For example, I will typically make a run of 3,4,5, or even 6 beers, each with increasing sugar content in order to make stronger beers of a certain style. Originally I did this under the surmise of higher yeast populations being able to digest the higher sugar content worts as found in big(ger) beers. While I had no idea as to why there would be different populations after 3 or 4 brews, this article fully explains the causes and reason for the heterogenicity of yeast cultures in the medium after several generations. Mutations are a normal variant of yeast reproduction, and can be demonstrated in a home brew setting within a very short period of time. It’s interesting to point out that it’s the mutative feature of yeast that allows for this phenomena to occur, elsewise we wouldn’t be able to grow up enough ethanol tolerant yeast to make some of our favorite beer styles such as Barleywines, and Russian Imperial Stouts! Since I brew a lot of Belgian style beers, it was of necessity that I brewed this way so I could get not only the traditional level of alcohol as found in these styles of brews, but also to make them dry enough to be as drinkable as possible. This might also explain why historically we see beers increasing incrementally in intensity as the wort composition increases in gravity. One experiment I have done, and encourage everyone else to try is to make a series of beers within the same family of beers, slowly increasing the original gravity with each successive brew. Then compare these beers to one made with a sufficient quantity of active healthy yeast for fermentation to finish the beer to its terminal gravity. My results always showed that I got better results by using the aforementioned method of increasing wort gravity over a simple single brew made with adequate yeast. Apparently the mutating yeast account for the difference, and makes for a more complex, and therefore superior beer in my humble opinion. Let me know in the comments section what your results are and I’ll publish a tabulation of those results here for everyone’s benefit.

Fermentation Chart

Notice the decreasing return on ethanol production with increasing sugar content in this graph. Very typical of a homofermentive population.

Advertisements

Please Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 2,754 other followers

beer sensory science

Dedicated to understanding the science of beer flavor

The Apartment Homebrewer

Brewing small batches of craft beer in a 650 sqft apartment

World's Oldest Home Beer & Wine Supply Store

Seacoast Beverage Lab

World's Oldest Home Beer & Wine Supply Store

The Not So Professional Beer Blog

World's Oldest Home Beer & Wine Supply Store

The Beer Here

World's Oldest Home Beer & Wine Supply Store

Beervana

World's Oldest Home Beer & Wine Supply Store

-=BrewmanceNW=-

World's Oldest Home Beer & Wine Supply Store

#pdxbeergeeks

World's Oldest Home Beer & Wine Supply Store

BREWPUBLIC.com

World's Oldest Home Beer & Wine Supply Store

%d bloggers like this: