Sonoma County's Growing Regions

I think it's time we talked about Sonoma County's wine growing regions.

First a map to help orientate yourself.... (Map courtesy of the Sonoma County Winegrape Commission)

Sonoma County is very unique. It is the only growing region in the world that has climates of very cool, cool, warm and very warm (some would say cold to hot) all within the confines of one AVA - American Viticulture Area. AVA's are controlled by the Alcohol and Tobacco Tax and Trade Bureau. Wineries can petition to create new boundaries, but it is a difficult process.

Temperature highs in these AVA's, during the growing season (April - October), can range upwards of 40 degrees in some cases. In addition temperature swings from overnight to the hottest part of the day can range 40-plus degrees as well. All great things when growing grapes.

I'll start tonight by covering the AVA's encompassed by Sonoma Valley. Sonoma Valley has three AVA's within its borders. These are areas that have significantly different temperatures and/or soils than the larger AVA.

Los Carneros (The Ram):
Los Carneros, usually referred to as just "Carneros" spans both Sonoma and Napa Valley's. Sonoma's portion is cooler due to winds coming off the ocean and San Pablo bay. Soils are primarily clay and the top soil is not deep causing drainage problems. The Most common grapes in the region: Chardonnay, Pinot Noir, Syrah and small amounts of Pinot Blanc and Merlot. A majority of the grapes in this region are used for sparkling wine production.

Sonoma Valley:
Cool on the southern end and warm on the northern end, Sonoma Valley (like Napa Valley) can have a wide range of temperatures. There is also a set of mountains that help with controlling wind and rain. The Mayacamas to the east and Sonoma Mountain to the west. As a result, there is valley floor fruit as well as hillside fruit. There is a significant difference between the two, with hillside grapes generally more stressed producing smaller berries and more concentrated flavors. Soils range from clay on the floor to volcanic in the mountains. It is an area where many types of grapes will grow including: Rhone and Bordeaux varieties, Italian and German among others like Zinfandel. There are nearly 40 different grapes growing in this one region. AVA's within Sonoma Valley: Los Carneros, Sonoma Mountain and Bennett Valley. Fun fact: The first grapes were planted in Sonoma Valley in 1824.

Sonoma Mountain:
Sonoma Mountain AVA is small, but diverse. The terrain varies significantly throughout the area. There are little pockets where only certain grapes will grow. Sometimes fog will sit in pockets for hours longer than the surrounding areas. Up in the higher areas mostly Cabernet Sauvignon is grown, but the lower areas have grapes ranging from Chardonnay to Syrah, Grenache and Mourvedre. It is one of Sonoma County's smallest AVA's.

Bennett Valley:
Sonoma County's newest AVA, Bennett Valley, is one of the area's coolest regions. With fog and wind influence from both the Pacific Ocean and San Pablo Bay, it consistantly runs 5-7 degrees cooler than neighboring Sonoma Valley. Although, on significantly foggy days this range can be upwards of 20 degrees. Soils range from clay to volcanic, much like Sonoma Valley. But Bennett Valley has a rock in the soil called basalt that can impart a smokey characteristic on the wines. Grapes grown in this area include Chardonnay, Merlot, Pinot Noir and small amounts of Granache and Syrah. Cool fact: Bennett Valley only has one winery open to the public daily.

That's all for tonight. Next time we'll tackle the regions of Russian River, Dry Creek and Alexander Valley.

Cheers!