Christine Vernay was on holiday in Missouri when she got the call. It was August 12 2003 and the French vineyard owner was not due to return home for 10 days; the harvest on her Rhône valley estate would begin in late September. But then a friend from the same village, Condrieu, called her husband’s mobile phone. “The grapes have ripened early. You need to come home now,” he said.

France was sweltering in the most extreme heat wave on record. Christine and her husband, Paul Ansellem, caught the first flight back but by the time they reached the vineyards most of the grapes in their 18 hectare estate had shrivelled on the vine.