Proof: The Science of Booze

by Adam Rogers

“Fifteen years ago I would have said to you that all sulfur compounds in wine are negative,” says Hildegarde Heymann, a sensory scientist at UC Davis. In wine, sulfur shows up chemically as thiol groups and mercaptans like hydrogen sulfide. “But in the last fifteen years we found the volatile thiols that are the reason New Zealand Sauvignon Blanc smells like New Zealand Sauvignon Blanc. The gas chromatography work finally got to the point where they could see them. You could smell them—cat pee, passion fruit, tropical, grapefruit—they would have used those words, but we couldn’t have attached compounds to them. And once we know what the compounds are, we can say, how can we go back and manage these compounds?”