American Viticultural Areas (AVAs): Do They Make Sense?

Americans have never been particularly adept at geography. Since most would fail to locate Kansas on an unlabeled map of the United States, how would they fare with finding Chambolle-Musigny? This is why the American practice of naming wines by grape name is so successful for marketing

However, winemakers everywhere–from California to France–insist that wine is ‘made in the vineyard,’ and that location matters. Europeans have long had a rigidly codified appellation system that controls, among other things, the origin of grapes for wine. In a half-hearted way the American wine industry has adopted a superficially similar system–establishing American Viticultural Areas or AVAs. The half-hearted aspect is shown by the fact that regulations only require that 85% of the grapes come from the specific AVA. By contrast, in all European appellation systems, all the grapes must come from the designated geographic area indicated on the label.

To test the theory that–despite the shortcomings of our AVA system–location does help determine wine’s character, I spent two days in the Stags Leap District, one of Napa Valley’s 14 AVAs and visited eight of the roughly twenty wineries located there. During my visits, I compared–sometimes blind–producers’ Cabernets labeled with a Stags Leap District appellation to their Cabernets that carried another AVA, usually Napa Valley (which means that 85% of the grapes came from anywhere within Napa, including some from Stags Leap District). In addition, I spent several hours in the AVA Room at Conn Creek Winery where I tasted wines made with exactly the same winemaking techniques from grapes grown in the different Napa AVAs.

Stags Leap District

I’ll report the results of my comparisons in next month’s column. But first, some background on Stags Leap District.

Stags Leap District is small–its 1,300-planted acres comprises less than 5% of Napa Valley. The wineries there focus on one varietal, Cabernet Sauvignon, which accounts for over 80% of the plantings. It is home to the 1973 Stag’s Leap Wine Cellars Cabernet Sauvignon that astounded the world in the 1976 Paris competition and instantaneously added California to the places where great wines are made when a panel of French judges declared it the winner, preferring it over 1st Growth Bordeaux in a blind tasting.

Boundaries: The Devil’s in the Details

Drawing appellation lines anywhere is inherently controversial business. Which Burgundy vineyards deserve Grand Cru as opposed to Premier Cru status? What are the limits of Coonawarra? The results are always a compromise between geography and politics, and the boundaries of the Stags Leap District are no exception to this general rule.

The Stags Leap District is a valley within a valley, bordered by the Vaca Mountains with their eye-catching palisades on the East and the Napa River and a series of small hills to the West. The northern limit is the Yountville Cross Road, while the southern end extends to just north of the city of Napa. Even today, 20 years after the Stags Leap District AVA won approval, many winery owners think the boundaries should have been drawn differently, arguing that the soil or climate at the southern end and near the river is substantially different from the rest of the district and should not have been included.

Politics may well have influenced the size of the district, since Robert Mondavi owned 500 acres in this part of the AVA at the time the boundaries were drawn. Others, such as Larry Mcguire, President and CEO of Far Niente and a partner in Nickel and Nickel (whose wineries are not located in Stags Leap District, but who is very knowledgeable about the region because Nickel and Nickel makes a variety of single vineyard wines, including one from the Stags Leap), insist that vineyard land just north of the Yountville Cross Road should have been included.

John Shafer, founder of Shafer Vineyards, and Richard Steltzner, founder of Steltzner Vineyards, were early advocates of the uniqueness of the wines from Stags Leap District and were instrumental in gaining governmental approval for the AVA. According to Shafer, it was a seemingly endless struggle–taking five years–that even included negotiations over the apostrophe. To satisfy Stag’s Leap Wine Cellars and Stags’ Leap Winery, who had already battled each other about their names (and apostrophes), the official name of the appellation would contain the word District (other Napa AVAs just use the name of the area, such as Oakville or Rutherford) and would omit the apostrophe.

What Makes Stags Leap District Unique

The botanists and others at the University of California at Davis (the country’s premier enology school) felt Stags Leap District was too cold for Cabernet Sauvignon to ripen adequately because of its cooling winds. But Nathan Fay planted his vineyard in 1961 with Cabernet despite their advice and sold the grapes to Robert Mondavi and Joseph Heitz, who made California’s first vineyard designated wine, Heitz’s Fay Vineyard Cabernet Sauvignon. There must have been something about those grapes that appealed to Warren Winiarski, who worked for Mondavi at the time. After Winiarski left Mondavi to establish his own winery, he could have purchased land anywhere in the Napa Valley, but he chose Stags Leap District for his new winery, Stag’s Leap Wine Cellars, and it was his wine that astounded the French judges.

Wind and Knobs

Winemakers and viticulturists point to soil and climate to explain why Stags Leap District is unique. Greg Brickey, who is extremely knowledgeable about Napa Valley AVAs because he is responsible for viticulture and relations with growers at Conn Creek Winery, notes that Stags Leap District is unique because it contains very few vineyards that sit on a valley floor with rich soils. ‘Most Napa AVAs run from one side of the valley to the other. Stags Leap District is much more circumscribed and smaller,’ which he believes leads to more consistent quality of the grapes.

Jonathan Emmrich, winemaker at Silverado Vineyards, notes the small hills–he calls them ‘knobs’–that jut up from the narrow valley floor and amplify the area available for hillside vineyards. ‘The knobs define the area. They stick up and expose volcanic soil, a well-drained, red rock, poor soil.’ He and Allison Steltzner, Richard’s daughter, cite these knobs and the adjoining mountains as providing a diversity of soils. Steltzner notes that even the soil at the valley floor–away from the Napa River–is ‘mountain-like’ because it was washed down over the millennia from the Vaca Mountains.

Everyone agrees that the narrow valley that comprises Stags Leap District allows cooling winds from San Pablo Bay–an extension of San Francisco Bay and hence the Pacific Ocean–to whistle through, especially in the afternoon. According to Shafer, the temperatures drop dramatically from a high of 90 and above during the day to 55 at night. He says, ‘We have Rutherford days, but Carneros nights, which not only hold the grapes’ acidity, but add a textural element.’ This dramatic diurnal temperature swing allows grapes to ripen during the day while preserving all-important malic acidity–which imparts freshness to the wine–at night (the breakdown of malic acidity is slowed dramatically below a temperature of 55 degrees).

Allison Steltzner agrees that the wind is crucial to the uniqueness of the district. ‘It not only cools, but it also promotes wonderful circulation. There is a funnel-like effect coming up from Carneros through the Stags Leap District that is most prominent in the afternoon, but it is frequently apparent in the morning.’ She also points out that this area of Stags Leap District is the first place in Napa Valley to break through the fog in the morning so it gets plenty of warmth to balance the cooling breezes.

Click Here for Part II

Questions or comments? What do you think about Stags Leap District Cabernet? Are they unique? Email me at

June 2, 2009