Brûlure is a French term that literally means ‘burn’. It is used to indicate stalks and grape bunches that have been damaged by being in the hot sun for too long. Grapes show a red-brown spot on the sun side which in extreme cases can cause the grape to burst and dry out completely. Defoliation, or defoliation too late, makes the clusters extra sensitive to burning. This is partly due to late defoliation because the bunch has hardly been able to adapt to the new warmer conditions, for example through the production of the flavonoids quercetin, kaempferol and myricetin (the latter mainly in blue grapes).