|Photo: Alexandra Boulat/AP|
"In wines made from the Sauvignon Blanc grape an odorant molecule has been found whose effect is registered only when the enzymes in saliva have separated it from its precursor. A few moments are needed, then, for the aroma to be perceived. In 1995, Philippe Darriet and Denix Dubourdieu discovered a molecule a boxwood or broom note. Significantly, this simple moecule, whose skeleton is composed of only five carbon atoms, contains a sulfur atom. Additionally, they observed that the frequency with which this precursor is transformed into an odorant molecule depends on the strains of yeast responsible for fermentation."There's not a lot more detail to be found, so it's difficult to know how much (if at all) this might be applicable to beer. But the idea that the perception of aroma or flavor (the two are strongly related) depends on chemical reactions that happen with the application of the taster's saliva--this is fascinating. When I hold beer in my mouth, flavors and aromas do emerge, but this may well be from warmth, which volatilizes aroma. It would be hard to tease the two effects apart from a sensory perspective. But I love the idea.
Update. The internet is like a little god. You stand in its dim light and pose your question. It is only a little god and therefore often remains mute. But sometimes it answers, and this time it said to me, "hop glycosides." I swear it spoke in the voice of Stan Hieronymus:
Looking beyond the lupulin gland, and compounds that mostly evaporate during a vigorous boil, led to the discovery of glycosidically bound flavor compounds in hops that contribute to the complex aroma and flavor matrix.... Unlike essential oils some of these glycosides survive the vigorous wort boiling process. Combined their parts are odorless and nonvolatile, but various yeast strains cause individual cleavage of glycosides, freeing the aromatic component and adding to what is called kettle hop flavor....(As with my Hervé This quotes, I streamlined this one a bit--you'll just go have to buy the book if you want the full quote.)
[Miller chemist Pat] Ting explained that this flavor does not result simply from hydrolyzed glycosides but also from the subsequent bioconversion by yeast and perhaps even enzymes and microorganisms in the mouth.