Botrytis cinerea, commonly called “noble rot,” is a beneficial fungus that’s needed to produce many of the world’s great sweet wines, including Sauternes and Tokaji Aszú. When noble rot attacks grapes, it covers them with a thin, gray mold that penetrates the grape skins. The mold multiplies by using water in the grapes to grow and spread. Without much water inside, each grape possesses a higher concentration of sugar, acid, and ultimately, flavor. The first intentionally botrytis-infected wines were made in the Tokaji region in Hungary in the early 1600s.
This wine word is from Karen MacNeil’s Dictionary of Wine Terms.