An ethanol spray at veraison enhances colour in red wines

Aqueous ethanol (5% v/v) was sprayed onto bunches of Vitis vinifera L. cv. Cabernet Sauvignon 8–9 weeks following full flowering (controls were sprayed with water). Internal ethylene concentration in treated berries increased to a maximum within 6 hours, and berry colour subsequently increased substantially (maximum attained 2–3 weeks after spraying). Berry fresh weight at harvest was unaffected by ethanol treatment, but wine made from treated grapes showed greater colour intensity compared with control grapes.