For twenty years, this beautifully designed winery perched on a mesa in the Santa Ynez valley north of Los Olivos has been producing wines with mixed results. Recent vintages suggest that the quality of the Chardonnays and Cabernets is moving upward. Firestone has long been known for its fine Johannisberg Riesling, but I found the 1991 to be tart, with only vague whiffs of apple fruitiness. Although competently made for uncritical quaffing, it lacks excitement. Tel. (805) 688-3940