Casual wine drinkers rarely get past the broad strokes. They love a rich Napa Cab, say, or a silky Sonoma Pinot. More avid fans tend to drill down: They’re partial to the firm tannins in the reds from Napa’s mountain AVAs, or the lean and earthy Pinots from far-west Sonoma. Few of us, even the wine geeks, can describe the signature traits of wines from individual vineyards. But for many top vintners, a wine that expresses the nuances of a single piece of ground—the soils, the aspects, the weather patterns—is the most interesting of all. And their life work is to elevate those nuances, to let them shine in a completely unique wine. And do it all over again in the vineyard next door, and the one across the county, all in the same year.