Weather damage could wipe out 20 per cent of Australia's wine grape crop this year. Excess rain has hurt nearly every wine producing area, with Sunraysia the hardest hit. Some Victorian growers could lose a third of their crop due to vine stress and disease. Mark McKenzie, from Murray Valley Winegrowers, says winemaking companies will make use of some of the damaged chardonnay grapes. "Wineries are getting in and are segregating some of the affected fruit and we believe some of that some of that chardonnay will go to concentrate production," he said.