While soil and climatic conditions can be diverse in the region, the BATF considers the cooling influence of San Francisco Bay a consolidating factor. Wineries can choose to use the new appellation on their labels as long as 85 percent of the grapes used in a wine are grown within the appellation borders.
Even though San Francisco is an urban area, according to a BATF statement, it was included in the appellation in deference to its place in California wine history.
Other recent decisions on California appellations:
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