Napa Valley's Dolce Winery is the only winery in North America that is devoted solely to producing a single, late harvest wine. The 1989 vintage, released in 1992, marked the first commercial release of the wine. By its nature, Dolce is a rare wine. It is produced by leaving ripe Semillon and Sauvignon Blanc grapes on the vine late in the harvest season and, if the right weather conditions occur, allowing a mold called botrytis cinerea, commonly known as noble rot, to attack the grapes. The botrytis shrivels the grapes, evaporating the water while concentrating the sugars and flavors.