Hops give ale prized floral flavoring but it comes with environmental costs. In the United States alone, producing these plants requires 100 billion liters of water per year.
Scientists, however, were able to genetically engineer yeast to produce brew with a flavor similar to those in naturally hopped beer, a process that can potentially make beer production more sustainable.
Yeast Infused With DNA From Mint And Basil
Charles Denby, from the Joint Bioenergy Institute in California, and whose work involves creating sustainable fuel out of plant molecules known as terpenes, learned that terpenes in small doses could impact the taste of hops, the green flowers used to give beer its bitter and citrusy flavor.
Denby and colleagues then decided to conduct an experiment. They infused brewer's yeast with DNA from mint and basil, which naturally produce hop-flavored terpenes. The engineered yeast was then used to brew hops-free ale.
In blind taste tests reported in the journal Nature Communications, the researchers said that people ranked the new brew they produced using the genetically modified yeast as hoppier compared with the traditionally hopped beer.
Lagunitas Brewing Company brewing innovation manager described the brew as having the flavor characteristics of Fruits Loops and orange blossom sans the unwanted off-flavors.
"Brewer's yeast can be engineered to biosynthesize aromatic monoterpene molecules that impart hoppy flavor to beer by incorporating recombinant DNA derived from yeast, mint, and basil," the researchers wrote in their study.
"Beers produced using these strains are perceived as hoppier than traditionally hopped beers by a sensory panel in a double-blind tasting."
Making Beer Brewing Process More Sustainable
As demand for craft beer boomed over the past two decades, Americans developed a strong preference for hoppy brews such as IPAs or India pale ales, which drive up demand for hops.
The irrigation of the crop in the United States, however, has become a growing problem for breweries. Many farmers can't keep up with the demand and brewers face hops shortage, which slows down the growth of the craft beer industry.
The researchers said that they are excited to make brewing process more sustainable.
"We come from a lab that's really focused on technologies that make processes more sustainable, cutting out all of the water and natural resources required for hop agriculture," Denby said. "The flavored hops are the majority of the hops that are grown in the U.S. for making beer. "