The harvest.

The harvest of the sauterne grape differs significantly from conventional methods.

In Sauternes, the grapes are left on the vines until they are affected by Botrytis cinerea, which perforates the skin of the grape.  Water evaporates through the perforations and the remaining juice is a concentrate.  This procedure is very complicated and depends on the micro climate before harvesting.

For the Botrytis cinerea to be successful there must be mist or light rain in the mornings followed by sunshine drying the grapes by lunch time.  During the afternoons sunshine and a light wind is required.  The Botrytis attack happens at different times on grapes of the same vine causing them to be ready for picking at different times.  The grape must be picked within a couple of days of the completion of the Botrytis process.  Therefore picking must be done at different times and only grapes which have finished the process can be picked.

As you can appreciate, their is a lot of criteria which has to be met for a successful Sauternes harvest:  the spring for budding and fruit formation; the summer for grape development; and the autumn with misty damp mornings and sunny afternoons.