What is the primary grape variety used in Sauternes wines?

The primary grape variety used in Sauternes wines is Sémillon. This region in Bordeaux, France, is renowned for its sweet wines that benefit from the unique climatic conditions that promote the development of noble rot, or Botrytis cinerea. Sémillon grapes have a thinner skin, making them more susceptible to botrytis, which concentrates the sugars and flavors in the grape, contributing to the rich, honeyed character of Sauternes.

While Sauvignon Blanc and occasionally Muscadelle are also included in the blends for Sauternes, Sémillon is the dominant variety due to its ability to age well and its complexity once affected by botrytis. The other grapes like Chardonnay and Riesling do not play significant roles in Sauternes production, making Sémillon the primary choice that defines the style and quality of these exquisite dessert wines.