A combination of mist and sunshine

The Sauternes appellation reaps all the benefits of the mild Aquitaine climate: wet, temperate winters and rainy, warm springs. These conditions encourage early bud break, but unfortunately exacerbate the damage caused by late frosts. Moderately warm summers ensure steady ripening, which is particularly favourable for white wines since it prevents the development of excess sugar and the resulting lack of acidity. Winegrowers forever are wary of the dangers of hail and violent storms that can destroy an entire harvest.
No sooner are concerns over spring and summer weather forgotten, that autumn arrives with its own particular, capricious characteristics. This magical season can make, or break, the vintage and is the time when the appellation’s microclimate makes all the difference.
Early morning mists occur from the end of September onwards, creeping up from the Garonne, and its colder tributary the Ciron. Walled in by the pine forest on one side, they cover the vineyards and create the right conditions for the development of botrytis cinerea, a microscopic fungus which grows on the grapes. By the end of the morning, the gentle heat of ; the rising sun disperses the mist, leaving a clear blue sky. The botrytis has just enough time to attack and perforate the skin, leaving the pulp untouched.
The magical phenomenon of noble rot has occurred, a peculiar fungus growth that absorbs water from within the berries to produce extraordinary must concentrations. The rot is first seen as brown spots, which extend steadily to cover the grapes. As the rot progresses the grapes become « fully rotten », start to shrivel and take on a crushed appearance, at which point they are described as «roti» (nobly rotted!). The moment has come for the harvest.

Since the ripening process is a function of grape variety, exposure, position of the berries in the bunch, etc., it is virtually always irregular. For this reason, the grapes are harvested not all at the same time, but are picked selectively as part of a process involving a series of separate harvests. Vines are inspected continually and only those bunches of grapes, portions of bunches or individual grapes which are « rotten » sufficiently are picked. Picking normally starts around the beginning of October and can continue until November or even December in extreme cases. In general, great growth châteaux go through the vines five or six times, although nine or ten times is not uncommon in certain years.
Only experienced, meticulous grape pickers from the region are entrusted with the selection process. They advance slowly and knowingly along the vine rows, carefully snipping with their highly sharpened secators as though practising some ancient religious ritual which forbids loud noises or sudden gestures. The use of a mechanical harvester in Sauternes would be impossible. No machine or robot could replace the trained eye and judgement of these pickers.
There are years when it is impossible to produce a genuine sweet wine since botrytis does not develop or does so to a limited extent. Excessive rain over long periods can destroy a harvest since the botrytis chemical reactions are modified and only grey rot occurs. The risk involved in the production of these great wines is thus very high. Prices, often considered too high by uninformed consumers, reflect both this risk factor and the high labour costs. A good indication of the restrictions imposed by this selectivity is that although yields are limited to 25 hl/ha in the appellation, the great growths actually harvest between 1O and 15 hl/ha.