Troels Prahl, a brewer and microbiologist at the Southern California yeast distributor White Labs, sits at his company’s tasting room bar with four half-pints of beer. He describes each between thoughtful sips.
After thousands of years of unwitting domestication, brewing yeasts — the microorganisms that ferment a brewer’s tepid slop of grain, water and hops into beer — are as diverse as the beer they make. And now two research teams, from White Labs and a Belgian genetics laboratory, are mapping out their sprawling genealogy, creating the first genetic family tree for brewing yeasts and the beers they make.
The laboratories have sequenced the DNA of more than 240 strains of brewing yeasts from around the world. By comparing the DNA of hundreds of yeasts, along with information on how they act and brew differently, “we’ll have a unique window into the genetic code,” said Mr. Prahl, who is leading the experiment at White Labs. He is comparing each yeast’s sequencing information with brewing data on more than 2,000 batches of beer — including the four he was tasting.
The researchers in the Belgian lab — a joint venture of the Flanders Institute for Biotechnology and the University of Leuven, Belgium — have even bigger plans. “With this information, we’ll be able to select different properties in yeasts and breed them together to generate new ones,” Dr. Verstrepen said. “In a few years we might be drinking beers that are far different and more interesting than those that currently exist.”
For brewers today, there are few options for generating new yeasts. Simply breeding strains together rarely results in a usable brew — because most brewing yeasts are highly specialized, the results are often the genetic equivalent of combining a bicycle with in-line skates. Each serves the same purpose, but applying parts from one to the other yields little more than a mess.
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And while the genetic tools already exist to create new yeasts artificially — by splicing genes from one to another — because of the longstanding stigma associated with genetically modified foods, there is no market for them.
“Right now we have a few hundred genetically modified yeast strains patiently waiting in our laboratory’s freezer,” said Jan Steensels, a microbiologist with the Belgian lab, “but most brewers and consumers don’t want anything to do with them.” The data from the genomic project could allow researchers to design and breed new brewing yeasts without resorting to genetic modification.
Read the full, original story: Craft Beer, at the Genetic Level
