Dessert Wines

One of the most extraordinary uses of a grape, it seems to me, is the sweet wines, or Vins Liquoreux, that are found in Sauternes, Barsac, and Monbazillac.

In Monbazillac a hill beside a bend in the Dordogne creates a pocket of cold air that in the autumn causes early morning mists. It is hot enough, though, for the sun to come up and rapidly burn off the mist, and these are the perfect conditions for the botrytis cinerea fungus, known as the Pourriture Noble, or the Noble Rot.

The botrytis first infects the grapes through tiny the wound caused when the flower drops off the budding grape in spring time. Nearly all vineyards spray to protect their grapes at this vulnerable time, but where the autumnal cliamte is right for the fungus to thrive, the botrytis is allowed to infect the grapes.

The grapes develop normally, but in mid September the fungus begins to take hold. The grapes dehydrate dramatically, concentrating the sugar levels in the grapes. In the best Monbazillac vineyards the concentrations of sugar reach as much as 700 ml per litre of grape juice.

The grapes are harvested late as the vignerons wait for rot to strike. The vendange, or harvest, is slow and expensive as the vignerons wait for each bunch of grapes to succumb. The yield is tiny - French tradition has it that a vine will yield a bottle of wine, or a glass of vin liquoreux - and these sweet wines can be very expensive.

The finest vin liquoreux in the world are produced at Chateau d'Yquem in Sauternes where the cold waters of the River Cerons cause the same autumn mists. At d'Yquem the grapes are harvested one by one as the rot takes hold, and their wine is more expensive even than the Premiers Grand Crus.

Served chilled, these wines can be exquisite, and if you're not familiar with them, then a day in Monbazillac will be a good introduction. One puzzle remains for me: a grape affected by the Pourriture Noble (Noble Rot) looks nothing less than disgusting. I'd love to know which rogue first looked at these shrivelled fungus-ridden grapes and thought: " They'll do!".