Sweet wine growers in the hills near Bordeaux have been left sour-faced after a village convenience store was fined in court for selling them tonnes of sugar — allegedly to make jam.

France allows growers to add grape must or sugar during fermentation in order to increase the degree of alcohol in their wine, but with strict rules on the quantity allowed. There is also a tax of 13 euros per 100 kilos of sugar.

The DGCCRF fraud prevention agency grew suspicious after granulated sugar sales turned brisk at Le Montecrucien convenience store, the only shop in Sainte-Croix-du-Mont, population 900, located 40 minutes from Bordeaux.