Napa’s Nested AVAs: Los Carneros

"Carneros is the southeastern-most AVA and is heavily influenced by its proximity to the San Pablo Bay. Carneros is generally the coolest AVA in the warm summer months, often covered by fog in the mornings coming off the bay. This provides for a slow, steady ripening of the grapes and wines that are fresh and vibrant, with natural acidity."
- Anthony Truchard II, Truchard Vineyards

"This region is more suited to the early ripening grape varieties - Pinot Noir and Chardonnay. These wines, when produced at our winery from Carneros region grapes, are significantly different in character to those produced from the same varieties grown in vineyards to the north of Carneros."
- Thomas B. Selfridge and Anthony A. Bell, Beaulieu Vineyard

The name Los Carneros translates to "The Rams" in Spanish and dates back to the 1830's when this region was owned by Mexico. Throughout the 1830's and 1840's, General Mariano Vallejo played a large part in the creation of many of Napa Valley Appellations through his practice of awarding large plots of land, or Ranchos, to friends and family. The area now known as Los Carneros AVA is comprised of at least three of these original Mexican land grants, Rincon de los Carneros, Entre Napa and Huichica Ranchos. The Ranchos Rincon de los Carneros and Entre Napa were given to Nicola Higuerra, a former soldier and Alcalde of Sonoma. Rancho Huichica was given to Vallejo's son-in-law, Jacob Leese.

Traditionally, the area that would come to be known as Los Carneros was dominated by large ranches and dairies. One of the first people to plant vineyards in Los Carneros was William Winter, who acquired 1000 acres of Huichica Rancho in the 1850's and by 1870 had one of the largest vineyards in the county. Winter was also the person to build the first winery in Los Carneros during the 1870's. Wine production in Los Carneros diminished during the outbreak of Phylloxera in the 1890's and then Prohibition in the 1920's. However, grape growing and wine production began in 1942 when winemaker Louis M. Martini bought the old Stanly Ranch property and other large producers began to recognize the potential of the area for cultivating grapes used in sparkling wine.

The Carneros region covers 58,000 acres located along the low-lying hills of the Mayacamas range as it descends underneath San Francisco Bay. Elevations of most vineyards range from 400 feet in the foothills to near sea level closer to the bay. The official boundaries of the AVA fall into both Napa and Sonoma counties with the largest portion being in Sonoma and entitled to use the Sonoma Valley AVA designation as well. The Napa portion of Los Carneros is similarly entitled to use the Napa Valley AVA designation. The region is moderately cool and windy with marked influences from nearby San Pablo Bay, making it the coolest and windiest AVA in both Napa & Sonoma. Early morning fog is a persistent feature. Receiving its AVA status in 1983, the Carneros area was the first wine region in California to be defined by its climate characteristics rather than political boundaries.

The soils of the Carneros region are predominantly clay and very thin and shallow, providing poor drainage and fertility. The fierce and persistent winds coming off the bay encourages the grapevines to struggle and retain moisture. While this aids in keeping crop yields small, it can also delay the grapes from ripening sufficiently. In vintages with a long, drawn out growing season that allow the grapes to ripen, intense and vivid flavors can develop.

Most vineyards are between one and four miles from the bay, meaning that with an average temperature during the growing season is only 72° F, it’s quite well suited to varieties that like more moderate climates, such as Pinot Noir, Chardonnay, but also Albariño, and Pinot Gris. Though there may be cooling influences there’s not a lot of rain, with only 25 inches of rain, most of which falls during the winter months.

Thankfully, the clay top soils found here hold moisture, which means vineyards don’t need to irrigate as much as you think. The loamy soils, particularly near Carneros Creek, are perfect for acid retention, which is a key component to producing high-quality sparkling wines. 50% of all grapes in Carneros are Chardonnay and 43% are Pinot Noir.

Los Carneros AVA is 37,000 acres with over 10,000 acres planted, 3,416 of which are in Napa Valley. Los Carneros is one of the coolest (temperature wise) appellations in Napa Valley. The other one is Wild Horse Valley. Here, Pinot Noir and Chardonnay dominate the plantings, and the resulting wines are delicate with Burgundian-style characteristics. Given the cool conditions, it’s also a spectacular site for producing sparkling wine.