Chenin and Riesling are two grape varieties that truly come into their own when the harvest includes noble rot, also known as botrytis. Its prevalence varies from about 5 to 15 percent, depending on the vintage. It should not be confused with late-harvest winemaking, which is a different viticultural practice.

As grapes ripen, they go through different stages of maturity, changing from green to ochre yellow, sometimes with a slight brown tint. Wine enthusiasts should not confuse this with oxidation.