25 miles south of the city of Bordeaux the confluence of the Garonne and its tributary the Ciron, in conjunction with the hilly geography of the area and sunny autumn weather, creates a misty early morning microclimate that is perfect for botrytis to begin and flourish. As the day warms up and the mist clears the botrytis is stabilised and remains in its benign form. Should damp, humid or rainy weather strike the vineyards all will be lost as botrytis transforms itself into the more pernicious grey rot, in which case no sauternes can be made. These unfortunate circumstances happen about twice a decade and add the already challenging economic environment for all but the wealthiest producers. Great pine forests to the west offer some protection from bad weather but making sauternes is a labour of love, perhaps even a labour of passion.

The Dubourdieu family owns 135 hectares of vineyards in the Sauternes, Graves, and Cadillac-Cotes de Bordeaux regions. They use a traditional ploughing system, and are committed friends of the environment: they no longer use weed killer, they fertilise the vines with organic manure, and all bud removal, trellising and leaf removal is done by hand. Their carbon footprint is a conscious issue too: they own a forest equal to the size of their vineyards as a way of repaying their debt to the land.

Although there are a few notable exceptions, much of the family’s vineyards are planted on the famous Barsac red sands, composed of red clay on a limestone subsoil. This slightly porous rock stores water throughout winter that can be dispensed to the vines during summer dry spells.

Semillon is the principal grape, useful because its thin skin is pierced easily by the botrytis to allow it to feed on the moisture inside, concentrating the grape sugars and glycerol, and heightening the acidity. The second grape is sauvignon blanc which makes up about 25% of plantings, while the fragrant muscadelle brings up the rear. Vines are carefully pruned and tended in order to encourage development of the fungus. Once the botrytis appears it affects bunches unevenly, both in terms of the individual grapes within the bunch and across the vineyard. It is necessary for pickers to make several passes, up to ten on the best properties, to pick even single grapes as they are affected, and each vine yields only enough juice for a single glass of wine. Sometimes the harvest can take two months to complete.