Kirin Brewery, along with the Keio University Institute of Advanced Biosciences have announced the discovery of new yeast strain found by analyzing the metabolic byproducts that brewer’s yeast synthesizes. What they found was that brewer’s yeast creates large quantities of “hydrogen sulfide when processing a tiny number of metabolites of the amino acid asparagine.” The team then selected yeasts that unusually prolific asparagine metabolites. The new strain “processes large amounts of sulfurous acid — an antioxidant that helps keep beer fresh — without synthesizing hydrogen sulfide, which has an unpleasant sulfur smell.” In fact, the new Kirin yeast makes 50% more sulfurous acid but no hydrogen sulfide whatsoever. Kirin plans to start using the new yeast in the beer shortly, presumably after more testing is completed. But if true, it could revolutionize the brewing industry.