Sauternes is an AOC, established in 1936, and located in Bordeaux, France. The region produces an unfortified sweet wine, that can be made with Semillon, Sauvignon Blanc, Muscadelle and Sauvignon Gris grapes. The AOC entails five different communes in the Gironde Department: Sauternes, Barsac, Bommes, Preignac and Fargues.
Sauternes is also a magical wine, as it is made with botrytis-affected grapes. The fungus Botrytis cinerea attacks the grapes, but instead of causing gray rot, the fungus infects the grapes in a benevolent way. The so-called noble rot will create new aromas and flavors, such as orange marmalade, honey, and dried fruits, concentrate sugar and acid in grapes. To achieve that, ideal climatic conditions must be met, such as misty and humid mornings followed by sunny afternoons.
Sauternes is the perfect place for these circumstances, because of its special microclimate. The cool river Ciron and the warmer Garonne encounter to create evening and early morning mists during the autumn. If the weather is good, the sunny afternoons will make the mist disappear, drying out the grapes. But there is always the risk of not having these conditions; in rainy and cool vintages, for instance, botrytis may not develop, or gray rot can damage the harvest.
While I was studying for the Diploma (WSET Level 4), I saw the market importance of the Sauternes region, and also read about the low yields, with some properties working with 9hl/hectare, and the maximum yield permitted in the region being 25hl/hectare. I also learned the difficulty of harvest, as it has to be hand harvested and done in multiple passes.
Now as a WSET Educator, we taste Sauternes at the WSET Levels 1, 2 and 3 courses, and students are always impressed by the quality of these sweet wines.