The white liquoreux wines all come from one area which enjoys a very special microclimate thanks to the Ciron, a little river that comes down from the Landes to meet the Garonne right in the centre of this region.
Cooler, because it winds its way under the trees, the Ciron causes a mist that induces the formation of the botrytis cinerea mould.
This fungus favours water evaporation from the grape flesh, thus increasing the sugar content and aroma concentration.
Grape-picking sometimes extends into December, and is done in successive sessions, day after day, to pick only healthy grapes, exposed to botrytis, and which have reached full maturity.
At the confluence, the terroirs are varied and the subsoil complementary. On the left bank of the Garonne, terraces of gravel mixed with stretches of clay for Sauternes production, clay and limestone for Barsac, gravel and a limestone plateau for Cérons. On the opposite bank, a limestone hill vineyard for Sainte-Croix du Mont and Cadillac, and some extra clay for Loupiac. This diversity gives its uniqueness to each appellation.
In the main, liquoreux wines keep very well.