Bjornstad Pinot Noir, Hellenthal Vineyard 2006 / 750 ml.

Sonoma County, just north of San Francisco is one of California's most famous wine districts. While sometimes overshadowed by the reputation of its rival and neighbor, Napa Valley, Sonoma County has a longer history of viticulture and is twice the size of the former.

Thanks in part to a strong diversity of climates within Sonoma County, the district is home to outstanding examples from a whole host of grapes. Sonoma County Pinot Noirs are considered some of the finest in the state, and the Dry Creek Valley Zinfandels are remarkable. Chardonnays come in a variety of styles thanks to the varying temperatures in Sonoma County, and Cabernets and Merlots also thrive here.

Some of the more celebrated viticultural areas in Sonoma County include Sonoma Mountain, Sonoma Coast, Chalk Hill, Dry Creek Valley, Alexander Valley, and Carneros (parts of which fall within Napa Valley).

When it comes to US wine production, California is King. California wines account for almost 90% of all wines produced in the United States each year, and is home to the most celebrated vineyards and producers in the country. California is probably best known for its world-famous Cabernets and Chardonnays, many of which hail from its two most-acclaimed AVAs, Napa Valley and Sonoma County. Other prominent grapes used in California wines include Merlot, Pinot Noir, Sauvignon Blanc, Syrah, and Zinfandel (which California made popular).