Washing Grapes Before Mechanical Harvesting

Abstract

The dust content of grapes in New York vineyards was found to range from 2 to 47 ppm and averaged 19 ppm for the three-year period of this study. When the grapes were washed on the vine with sprays of water from conventional vineyard sprayers, the dust content could be reduced by approximately 30%. The effectiveness of the washing was determined by the density of the foliage. The foliage of grape vines grown on Umbrella trellises was denser and more difficut to penetrate than that of vines grown on the Geneva Double Curtain, where the grape clusters were more exposed to the water sprays. Hand-harvested grapes are washed at the factory, but their dirt content does not appear to be significantly lower than that of fruit on the vine, owing to contamination during shipping. Under New York State conditions, if would appear possible to obtain as clean grapes by mechanical harvesting without washing as is now possible by factory washing of hand harvested fruit.