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Researchers have made a new beer yeast that creates a hop flavor.

Mike Pomranz
March 21, 2018

Yeast may be beer’s most overlooked ingredient. After all, while we owe a brew’s color to malts and hops are all the rage, the flavor yeast imparts can be subtle—and even overlooked. And yet, if a group of scientists has their way, yeast may soon be in the beer spotlight. U.C. Berkeley researchers have developed strains of yeast that pull double duty: it aids in the fermentation process and also creates its own hops-like flavors.

How have they done it? According to Inside Science, the scientists were working on a way to alter yeast DNA so that it would produce oils that could be used as biofuels. Instead, the scientists also stumbled on a way to create terpenes, a compound that is found in hop oils that adds flavor to beer. And from there, they set out to alter brewer’s yeast in specific ways, adding in genes from mint and basil plants to produce the floral notes found in some hop varieties. After plenty of experimenting and tasting, the duo landed on three strains that were able to impart hoppy notes without negatively affecting fermentation.

To test the final results, the researchers brewed four batches of beer—one with each of the three new yeast strains and an American pale ale brewed and hopped the traditional way. Then, they ran a blind taste test with employees at Lagunitas Brewing. Tasters were asked to rank the beers based on how hoppy they tasted. And in the end, according to Inside Science, the engineered yeast beat out the traditionally brewed pale ale.

Of course, “hoppier” isn’t inherently synonymous with “better,” and the scientists behind the findings admit that this work is just the beginning. “The methodologies … provide a foundation for generating more complex yeast-derived hop flavors,” the study states, “and broaden the possibilities of yeast-biosynthesized flavor molecules to those throughout the plant kingdom.”

Meanwhile, though the authors admit that there’s “historic consumer trepidation towards genetically engineered foods,” they also point out this method has a major benefit of its own: using yeast to produce hop flavors could significantly decrease the resources that go into growing hops, offering a more sustainable option. In fact, one of the researchers, Charles Denby, has launched a company to continue to work on developing these yeasts. He told Inside Science that the environmental benefits were what mattered most. “That's what we're passionate about,” he told Inside Science, “and that's why we are working hard on it.”