Riesling

Riesling is the most transparent white grape there is. It carries site differences more faithfully than almost anything else, it is almost never improved by oak, and it holds enough acidity to make a wine that is both very sweet and completely refreshing. It is first recorded in the Rheingau in 1435 and is a crossing of gouais blanc with a wild vine and traminer.

It is late ripening and cold hardy, which is an unusual combination and the reason it succeeds in northern Germany. The high natural acidity does three things: it lets the winemaker stop fermentation early and leave sugar without the wine tasting cloying, it preserves the wine for decades, and it makes low-alcohol wine taste complete rather than watery. With age riesling develops a kerosene note from a compound called TDN, which is prized by people who know the grape and alarming to people who do not.

The Mosel makes the lightest and most delicate versions on blue slate, the Rheingau and Pfalz make fuller ones, and Alsace and Austria make them dry. Clare and Eden Valleys in South Australia make dry riesling with hard lime acidity. The Finger Lakes in New York, and Washington, are the American homes. Almost none of it is expensive relative to its quality, which is the grape's persistent commercial problem.