The 230 acres of Château Rieussec are situated on the "communes" of Sauternes and Fargues, high above the Garonne River, in a small area where the cold Autumn dawns help form the famous mist. Many people believe this mist plays a major role in the development of botrytis cinerea (noble rot). Château de Cosse, the second label to Château Rieussec, is selected from barrels that have the same base as the "Grand Vin". Its characteristics are very similar to the "Grand Vin", but with shorter ageing in barrels. The wine may be enjoyed at a younger age than its counterpart, and possesses the typical characteristics of a fine Sauternes.