Gavin Sherlock, an outstanding scientist in the Department of Genetics at Stanford, and his coworker Barbara Dunn, have published a fascinating paper on the genetic heritage of the yeasts used in brewing lager beers and ales. They has used microarray hybridization to show that lagers (which are only about 600 years old) are a hybrid of two different yeast parent strains. Most interestingly, they found that the yeast used in different breweries can be distinguished and take on specific characteristics. This is probably known to the brewers, who I bet have engaged in yeast espionage and kidnapping for many years. Now they need to be careful: Gavin and Barbara have the tools to demonstrate who stole whose yeast. Gavin was interviewed about all this on NPR recently. Once again, bioinformatics wields its awesome power to impact something very important: beer.