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Beer made with gene-edited yeast provides hoppy taste without the hops

Craft beer drinkers love their bitter, hoppy brews, making pale ales and IPAs a big part of the craft brewery bubble. But hoppyness comes at more of a cost than a brewery on every other gentrified corner. It can also be surprisingly unsustainable.

It can take 50 pints of water to grow enough hops for one pint of craft beer, and that’s without even considering the fertilizer and energy needed to grow and transport the crop. But now, researchers from the University of California, Berkeley, have developed new strains of yeast that can instill a hoppy flavor without the need for hops.

Most beer is made up of four key ingredients: water, yeast, hops, and barley. Varieties like pale ales and IPAs are known for their strong hoppy notes, which gives them refreshingly bitter flavors and aromas, but, as it is with all good things, there’s a catch.

“Growing hops requires a lot of natural resources,” Rachel Li, a UC Berkeley doctoral candidate who co-led the research, told Digital Trends. “Water for irrigation and energy for processing, transporting, storing, and refrigerating.” With the aim to lessen the environmental impact of growing hops, Li and her team landed on a genetically engineered yeast with hoppy flavors. “By using these yeast strains, hoppy beers can be produced more sustainably than they currently are.”

In a paper published this week in the journal Nature Communications, the researchers describe how they used the gene-editing tool CRISPR-Cas9 to engineer yeast that contains hop-like characteristics. They then had Charles Bamforth, a brewing expert from the University of California, Davis, use three of their best strains to craft a few beers, only using hops at the initial stage to add bitterness without flavor.

CRISPR works like a DNA scissor, snipping out a precise part of the genome and allowing new genetic information to be introduced. The tool has already been used to develop drought-resistant crops and cattle. Now, Charles Denby, Li’s colleague and business partner, said it’s helping make hoppy beer without the hops.

“By inserting genes from mint and basil, genes that are also found in hops and that are responsible for the production of molecules that impart hoppy flavor to beer, we have developed a strain of yeast that can produce hoppy-flavored beer without hops,” Denby said. “Taste tests of the beer brewed with our strains confirmed that the yeast added hoppy flavor and aroma to the beer. In fact, our beer was rated as hoppier than two beers that were dry-hopped.”

Li and Denby recently launched a startup called Berkeley Brewing Science, through which they aim to market their genetically engineered yeast strains to brewers. Beyond making hoppy yeast, Li said they’re hoping to use gene-editing to add more natural and unique flavors, while “enhancing the performance of industrial brewer’s yeast for more sustainable brewing.”

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