La Tour Blanche was founded in the 18th century. It is a 1er Cru Classe, located in the appellation of Sauternes. In 1907 the previous owner, Daniel Iffla, left the estate to the French government, on the condition that it created a school of Viticulture and Oenology. Currently, La Tour Blanche is, at the same time, a school and an estate. There are 37 hectares under vine, which are planted with 83% Semillon, 12% Sauvignon and 5% Muscadelle. The soil consists of gravel with clay-limestone subsoil. After the fermentation, the wines are aged in 100% oak new barrels for 16-18 months before bottling.
Three grape varieties are planted: Sémillon, Sauvignon Blanc, and Muscadelle. Sémillon is the principal grape, because it is especially susceptible to noble rot, Sauvignon is used for its naturally high acidity, whilst tiny proportions of the capricious Muscadelle are used for aromatic qualities. Sweet wine has been made here at least since the late 18th century. Its position is unique, close to two rivers, the broad Garonne and its small tributary, the Ciron. In autumn, the cool Ciron waters flow into the warmer tidal Garonne, evening mists develop that envelop the vineyards until late morning the following day, after the sun has burnt the mist away all that is left is moisture on trhe grapes that encourages noble rot or Botrytis cinerea. This fungus attacks grapes, causing them to shrivel, concentrating flavour sugars and acids. The wines were classified in 1855, the most prominent of which is Château Yquem, whose yields even in a vintage where noble rot is prominent, reach no more than 10 hl/ha.