Sonoma County has a long and rich history of wine production. There are thirteen viticultural regions within the county based on their climate and soils. Sonoma is capable of producing a wide variety of wines because these various pockets are all quite unique from one another, Rockpile and Dry Creek Valley are hot, dry climates where Cabernet and Syrah can flourish. The Russian River Valley and Sonoma Coast are cool climates with fog or ocean breezes moderating the warm days and cooler nights. Here then is a breakdown of the various viticultural appellations within Sonoma County.

Alexander Valley: Just South of Mendocino County, this is the northernmost appellation in Sonoma. Reds dominate the scene here, particularly Cabernet, Zinfandel, and Petite Sirah. Some of the coastal fog that benefits many other parts of the county makes it's way here, but it is largely an appellation of long, hot days.

Rockpile: This area has been growing grapes for over a century. Despite such a long history, Rockpile is unique in the fact that no winery has been established in the region. This appellation is high, rough country, aptly named for it schist soils. The environment stresses the vines to maturity and the elevation keeps the fog away and lets the sun shine down on the grapes, further advancing their ripening. This area is best known for producing excellent rich Zinfandels.

Dry Creek Valley: Just South and slightly East of Rockpile is the Dry Creek Valley appellation. This region displays the diverse nature of Sonoma itself. Anchored by the man-made reservoir of Lake Sonoma, the region is known for and produces large quantities of Zinfandel, Cabernet, and Syrah. However, the region also makes good use of Merlot, Sangiovese, Chardonnay, and Carignan. Many excellent producers are based here, and it has simultaneously been a home for small family wineries and giants like Gallo alike.

Knights Valley: This region is the farthest from the reach of the pacific ocean, and is also Sonoma's warmest appellation. All five Bordeaux varietals are grown here, but Cabernet rules the roost. Sauvignon blanc is also produced here in a very rich, full and fruity style.

Chalk Hill: This region is set apart from the rest of Sonoma County. It is unique for it's soil, which is made up largely of volcanic ash. It also sits on the foothills approaching the mayacamas mountains and enjoys a higher elevation than most of Sonoma County. White wine is dominant here, particularly Chardonnay and Sauvignon Blanc. This region does also produce some great reds, notable among them are Merlot, Pinot Noir, and Cabernet Franc.

Russian River Valley: Defined by two things, fog and redwoods. While the trees don't have a tremendous effect over the vineyards, the fog has a major impact as it provides cool comfortable growing areas for grapes like Pinot Noir and Chardonnay. This region has become famous for its cool mornings and nights allowing the grapes to slowly reach physiological maturation, making for an excellent expression of the two varietals previously mentioned.

Green Valley: A sub-appellation within the Russian River Valley, Green Valley benefits from it's closer proximity to the Pacific Ocean's cooling and moderating effect. The lesser-known appellation, it is often labeled simply as Russian River wine on the bottle. The region is foremost for cool climate varieties, with excellent examples of both Pinot Noir and Chardonnay, and even harboring some Alsatian varietals such as Gewurztraminer.

Sonoma Valley: Although this appellation is fairly small, it has numerous sub-appellation based on widely varying soil and climate differences. The majority of the region is bordered on the West by the Sonoma Mountains. These cause a rain shadow in the region, so rainfall is quite limited in the area. Cool winds blow from the San Pablo bay to the South and through a gap in the mountains to the North. This keeps the growing area moderately cool in some sub-appellations of the larger region. This is also the first area North of San Francisco where grapes were planted.

Bennett Valley: A fairly new appellation, Bennett Valley is at the North-west corner of the larger Sonoma Valley region. Just South of the town of Santa Rosa, this region enjoys some coastal cooling effect but also reaches up into the Sonoma mountains range, giving some variety to the climatic conditions here. Grapes range from Chardonnay and Pinot Noir to Syrah, Merlot and Sangiovese.

Sonoma Mountain: High Elevations, steep vineyards, well-drained soil and an Easterly exposure make this a fine place to grow elegant Cabernet Sauvignon. There are also smaller micro-climates that hold pockets of cooler air, permitting the production of other varietals including Pinot Noir, Chardonnay, and Sauvignon Blanc.

Los Carneros: This wine region is unique for two particular reasons, the first is that it stretches between Napa and Sonoma counties. The second is that it sits just North of the San Pablo bay, on the other side of which is San Francisco, fog city. This region is excellent for cool climatic conditions, and Pinot Noir and Chardonnay both thrive here. The winds from the bay and the fog that rolls in daily help to allow grapes to reach physiological ripeness in good time. The region is also well known for producing methode champenoise sparklers from those same Chardonnay and Pinot Noir grapes.

Sonoma Coast: This region stretches the entire length of Sonoma County, from Mendocino to the North to Marin county in the South. The region is directly affected by the cool ocean breezes and fog provided daily by the Pacific ocean. This can be both a blessing and a curse as some vintages are under-ripe or experience too much moisture and rainfall, while others produce some of the best Pinot Noirs this side of Burgundy. The land itself looks like Ireland, everything is green except the coastal cliffs. There is much discussion of further dividing this Appellation into sub-appellations, especially considering the region's incredibly large size. Some AVA's are already being suggested, and the wine-press has already begun to refer to some regions with their own names, for example, Fort-Ross/Seaview and the Sebastopol hills. These are not officially appellations yet, but are likely to develop as such.

-Matthew Palmer, Photo: Erin Palmer