(Decanter) - Sudden and heavy rainfall across Bordeaux is forcing winemakers who have not yet harvested their reds to speed up picking or risk waiting longer for conditions to clear.

After the driest September in Bordeaux for 60 years, the return of the rain after a wet August is affecting picking schedules across the region, and is thought to mainly affect this year’s Cabernet Sauvignon and Cabernet Franc grapes.

Philippe Cohen of Chateau Vieux Taillefer in Saint Emilion told decanter.com that his Merlots had already reached full ripeness and that almost all had been picked before the rain started.

‘We will now wait until after the rain has passed, and bring in our Cabernets on Monday or Tuesday,' he said.

‘The threat of rot is back, as we are at 25°C, so we can’t wait too much longer. But luckily September meant that the vines had pretty much caught up after the problems in August, and we are still very happy with the quality.’

While the rain is causing a hindrance for some estates, oenologist Pascal Hénot downplayed its impact, highlighting the diurnal difference in the region, and lateness in the season as risk minimising features.

‘The rain of course brings with it the possibility of dilution and rot. Luckily it is not too warm during the day and cold at night, so the risk of rot is very low, and the grapes are in a good state’, said Hénot who works at Oenocentres, a laboratory working with over 300 estates and 25 cooperatives across the Gironde and the Dordogne.