Widely Varied Microclimates
The Bay Area Region is a radically diverse area, both in its geography and proximity to the ocean, creating a variety of microclimates. This widely varied region includes the Livermore Valley and Contra Costa County to the east of San Francisco and the Santa Cruz Mountains and Santa Clara Valley to the south.
The style and character of the cool climate wines from the Santa Cruz Mountains differ from those grown in the warmer vineyards of the Livermore and Santa Clara Valleys. Most vineyards in the Santa Cruz Mountains are planted in upper elevations and are not irrigated. The cooling ocean influence, as well as the well-drained soils of the area, yield densely extracted, spicy fruit.
The Livermore Valley experiences early morning fog from San Francisco Bay, followed by warm, sunny days, and cool evenings when the fog is blown back into the valley and held there by the surrounding mountains. Soil here is rocky and well drained. Contra Costa County, about 50 miles east of San Francisco, is also dominated by rocky, well drained soil, and there are still a few century old vineyards in this area. Zinfandels from this growing area tend to be rich and soft with intense plum and cherry flavors.
The American Viticultural Areas of the Bay Area are Ben Lomond Mountain, Contra Costa County, Livermore Valley, San Francisco Bay, San Ysidro District, Santa Clara Valley, and Santa Cruz Mountains.