On Food and Cooking

and tropical fruits, flowers, leaves, wood,
spices, animal scents, cooked foods of all
kinds, even fuel tanks and nail polish
remover. That’s why wine can be so evocative
and yet so hard to describe: at its best, it
offers a kind of sensory microcosm. And that
little world of molecules is a dynamic one. It
evolves over months and years in the bottle,
by the minute in the glass, and in the mouth
with every passing second. The vocabulary of
wine tasting thus amounts to a catalogue of
things in the world that can be smelled, and
whose smell can be recognized, however
fleetingly, in an attentive sip.
A few of the aromatic substances in wine
are contributed directly by particular varieties
of grape, mainly the flowery terpenes of some
white grapes and unusual sulfur compounds in
the Cabernet Sauvignon family. But the
primary creators of wine aroma are the yeasts,
which apparently generate most of the volatile
molecules as incidental by-products of their