If you have read the Riesling guide here, you know the grape barely has a personality of its own. It reports the place it grew instead of flavouring it. Two weeks ago we tasted that idea in Washington. This week we taste it in New York, and the two wines could not be more different. Same grape. Two climates. The gap between them is the whole lesson.

Washington grows its Riesling in a warm, sun-drenched high desert behind the Cascades. The fruit ripens fully and generously, so the wine comes out riper and rounder: peach and apricot and lime, with a kiss of sweetness, the gentle off-dry style that tames salt and spice at the table. Warm place, generous wine.

The Finger Lakes does the opposite. It is cold and marginal: glacial lakes, shale slopes, a short hard summer. The fruit never fully softens, the sugar stays low, the acid stays screaming. So the wine is bone-dry, lean and cutting: lime, green apple and underripe peach over wet stone, with no sweetness at all and an acidity that races. Cold place, austere wine.

Here is the principle worth carrying out of the week. Warmth gives you ripeness and roundness. Cold gives you acid and cut. Move the same grape to a colder, more marginal place and the fruit pulls back while the acid steps forward. It is true far beyond Riesling; it is why cool-climate anything tends to taste leaner and racier than its warm-climate twin. But Riesling shows it most plainly, because the grape adds so little of its own that the climate is almost all you taste.

Neither is better. They are answers to different questions at the table. The off-dry Washington wine is the one for a little heat or a salty-sweet plate. The bone-dry Finger Lakes wine is the one for raw fish, oysters, anything where you want the wine to cut, refresh, and then get out of the way. Which brings us to Thursday.