Wines include cabernet sauvignon, pinot noir, merlot, chardonnay, riesling and a white zinfandel. Ridge Vineyards is a California winery specializing in premium Cabernet Sauvignon, Zinfandel, and Chardonnay wines. Recent plantings include Sangiovese, Syrah, Tempranillo, Trebbiano, Pinotage, Malbec, Barbera and Zinfandel. Wine grapes, specifically zinfandel and syrah, are also still grown. White Merlot is made the same way as White Zinfandel. Some uniquely Californian styles are also made from Zinfandel and Petite Sirah. Turley specializes in wines made from old-vine red Zinfandel. White Zinfandel is a thin, slightly sweet blush wine. Some Italian winemakers age the wines in new American oak to imitate American-style Zinfandel. Zinfandel (also known as Primitivo) is a variety of black-skinned wine grape. Most white Zinfandel is made from grapes grown for that purpose in California's Central Valley. Joseph W. Osborne may have made the first wine from Zinfandel in California. Amador County has a high percentage of old Zinfandel vines. Ridge Vineyards produced its first Zinfandel in 1964. The first wine made from these California vines in 1975 also seemed identical to Zinfandel.