As whiskey takes off in popularity around the globe, con artists aren’t far behind. Because their “sham drams”—cheap, blended whiskeys masquerading as expensive single-malt scotches—are hard to ID without a master distiller, teams of chemists have designed all sorts of methods for picking out the fakes. But they require deep knowledge of the liquor’s complex chemical constituents, something your average barfly isn’t likely to have. So a group of German researchers came up with a simpler approach: using fluorescent dyes to compare different drinks. The dyes, which are synthetically produced, give off different colors depending on the molecular makeup of the brew. Comparing 33 different whiskeys in a head-to-head competition, the team was able to classify the fluorescent signals into groups based on country of origin, blending status (single malt or blended), age, and taste (rich or light), the team writes today in Chem. The sensor can’t definitively identify a whiskey, but it can be used to compare a questionable sample to a known one. The same scientists have also used the fluorescent dyes to differentiate between white wines, fruit juices, drugs, and proteins, and they suggest such sensors could be used in the future to weed out counterfeits and impurities in foods, drinks, drugs, and perfumes.