Terroir - Soil and climate

Situated on a low plateau sloping towaeds the Garonne, the diversity of soils and sub-soils give the various Sauternes vineyards their special personality.

However, what gives them their extraodinary originality is the frequency of morning fog in autumn, which is quickly dispered by the heat of sun.

The Ciron river is chiefly responsible for this. It used to join the Garonne at Cérons, but its course was diverted during the 16th century by the Benedictine monks. Nowadays it flows into the Garonne between Barsac and Preignac.

This morning humidity followed by warm sun encourages the proliferation of "noble rot" on the ripe grapes. This fungus, called "Botrytis cinerea", penetrates the grapes via stomata and causes the fruit to shirvel, thus concentrating the juice contained within the pulp and increasing the sugar content.