The Cabernet Sauvignon grapes on the right were treated with the kaolin clay product Surround. Photo courtesy of Ste. Michelle Wine Estates A kaolin-based particle film used to control pests and sunburn in tree fruit may have application in wine grapes as well. Though some winemakers are concerned with residues on the grapes from the particle film, studies by university researchers have not found an adverse effect on commercial winemaking practices. In two separate studies, both Dr. Christian Butzke, University of California Cooperative Extension enologist, and Philip VanBuskirk of Oregon State University reported that applications of the clay particle film sold […]