A huge, but largely low quality harvest is expected in Champagne following the highest recorded rainfall in the region since 1873. Botrytis also became a problem that affected around 25% of the grapes in the wet, humid conditions in early September, according to Moet & Chandon's head winemaker Georges Blanck.

"Rainfall has been 70% higher than usual and conditions are not very positive for grape maturation," says Blanck.

Picking in the wet would bring the already low potential alcohol down more. A problem made worse this harvest because individual grapes have already swollen to a record size and larger grapes take up water more readily. With the subsequent dilution and low levels of acidity it looks unlikely that much vintage champagne will be made.

With temperatures forecast to warm up this week, rot problems are likely to develop again, so selective picking will be very important. At least the large volume of grapes allows rotten fruit to be discarded. And because growers already hold in reserve the equivalent of half a harvest (5,500 kilos per hectare) if larger amounts of reserve wine are used in blending, the quality of non-vintage champagne should be assured.