San Francisco Bay AVA is one of California’s ‘Mega’ appellations. This vast AVA, covering over 1.5 million acres, is affected to varying degrees by coastal fog and winds from San Francisco Bay.

The AVA was created in 1999 after petitioning by Wente, one of California’s more influential wineries. The area encompasses the counties of San Francisco, San Mateo, Santa Clara, Contra Costa and Alameda, as well as parts of San Benito and Santa Cruz counties. Curiously, the appellation also includes San Francisco Bay itself and the City of San Francisco. Evidently, these latter areas were included to justify the validity of the appellation name. The appellation hosts a number of more ecologically-specific viticultural areas, each with its own distinct microclimate. However, the San Francisco Bay AVA could prove a valuable marketing tool for local wineries seeking name recognition in complicated international markets.

There are a number of micro climate zones around the Bay itself that harbor interesting small block vineyards whose fruit is sold to regional wineries or the amatuer markets. At the same time numerous 'Urban' wineries are now setting up shop at de commissioned military bases from Treasure Island (in the middle of San Francisco Bay and a part of The City) to Alameda and the old Naval Air Base. Wharehouse districts of San Francisco, Oakland and Emeryville are also finding wineries spring up as this trend elvolves.