Tuesday, September 1, 2015

Beer Capital of the World

In domesticating wild plants and animals over thousands of years and by selecting the most appropriate strains, people have changed the genomes permanently. For the first time molecular biologists at the University of Wisconsin-Madison have looked into genetic changes in domesticated yeast as it is used for beer brewing.

Red Baron already posted that beer brewing in the 16th century was not really understood. In fact, the German Beer Purity Law stated that only hops, water, and barley must be used for making beer but the necessary yeast was not mentioned. At the time of Goethe brewing was still an alleatoric process as undefined microorganisms in the environment entered the open mash and started its fermentation.

Nowadays beer brewers use well-defined yeasts that are hybrids of two Saccharomyces, i.e., S. eubayanus and S. cerevisiae (Latin for beer). For brewing lager-style beers two known S. cerevisiae are added to the mash: S. pastorianus syn. and S. carlsbergensis (sic). These yeasts recognized by brewers are also known as the Saaz and Frohberg lineages.

When comparing the known yeasts to their original wild forms Madison researchers found out that due to a lucky spontaneous hybridization in the 15th century the strain of yeast was formed that today is used for 90% of beer production. At that time at least another lucky hybridization happened so two lines of lager beer yeasts co-existed for quite a while. Dr. Chris Todd Hitting of the University of Wisconsin-Madison states that people have been unwittingly using yeast; mixing, matching and recombining different species without even understanding that microbes were involved in the process. So nowadays the two lineages are quasi identical. The Madison research scientists published a detailed account of their findings in the journal Molecular Biology and Evolution.


With this breakthrough in research on yeast Madison has become the beer capital of the world in particular when Dr. Hittinger continues: Investigating and discovering new lineages of yeasts involved in brewing beer opens up an exciting area for designer strains. The brewing industry could isolate more strains from the wild and hybridize them with strains well adapted to brewing conditions. It could be used to create novel flavors.

When Red Baron was a student in Munich he learned that Weihenstephan, a rather small town 30 kilometers farther north, was the world center for the science of beer brewing. The place was so famous that some of my fellow students seriously considered the possibility of transferring and getting a doctorate in beerology instead of science.

Apparently the problem of how to marry studies and excessive consumption of beer exists on both sides of the Atlantic. Here I quote an American student (original spelling): 4 years of college and all i have is a P.H.D. in Beerology!

By the way, the French call it la bièrologie. Note: also in France beer is more popular than wine among students.


©Laurel White/Madison.com
On the afternoon of Saturday, August 29, more than a thousand people gathered in the backyard of Madison's Ale Asylum for the Ferment Dissent Imperial Stout Riot & Festival. The attendants celebrated the release of two imperial stouts, both aged for one year. The two beers, a Russian imperial stout called Impending Descent and a Belgian-style imperial stout called Impending Dissent, are identical, except for the yeast strains they were fermented with. Are the new beers already the result of the research on yeast at the University of Wisconsin-Madison?

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