Before Cabernet Sauvignon became the most popular grape in the Napa Valley, most of the full-bodied red wines were made with Zinfandel, Petite Sirah, Charbono and other legendary grape varietals referred to as “mixed blacks.” During the Flavor! Napa Valley weekend, find out what the proprietors of Biale Vineyard, Hendry Vineyards, Turley Cellars and other boutique producers are doing to preserve these special old vineyard sites.