A given wine contains several hundred different kinds of volatile molecules, and those molecules have many different kinds of odors. In fact they run the gamut of our olfactory world. Some of the same molecules are also found in temperate 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.