Napa County vs Napa Valley AVA
Napa Valley AVA encompasses almost the entirety of Napa County. The one portion that is outside of the Napa Valley AVA is to the north and east of the Chiles Valley AVA sub-region - this specific area is mostly outside of Pope Valley, and has little if any vine cultivation taking place there.
Few wines are produced that carry a Napa County appellation of origin designation, as almost every wine produced from grapes grown in the county is eligible for release with the more commercially profitable Napa Valley AVA designation.
The most common use of Napa County on a wine label is when a wine has been produced from grapes grown in two or more counties, such as Sonoma County and Napa County. In such a case, the wine label must indicate what percentage of grapes were sourced from each county.
Napa Valley AVA
Napa Valley is an American Viticultural Area (AVA) located in Napa County in California's Wine Country. It was established by the Bureau of Alcohol, Tobacco and Firearms (ATF) on January 27, 1981. Napa Valley is considered one of the premier wine regions in the world. Records of commercial wine production in the region date back to the nineteenth century, but premium wine production dates back only to the 1960s. Within the Napa Valley AVA there are 16 sub-region AVAs from different portions of Napa County, one is shared with Sonoma County and another is shared with Solano County.
The combination of Mediterranean climate, geography and geology of the region are conducive to growing quality wine grapes. John Patchett established the Napa Valley's first commercial vineyard in 1858. In 1861 Charles Krug established another of Napa Valley's first commercial wineries in St. Helena. Viticulture in Napa suffered several setbacks in the late 19th and early 20th centuries, including an outbreak of the vine disease phylloxera, the institution of Prohibition, and the Great Depression. The wine industry in Napa Valley recovered, and helped by the results of the Paris Wine Tasting of 1976, came to be seen as capable of producing the best quality wine – equal to that of Old World wine regions. Napa Valley is now a major enotourism destination.
The valley floor is flanked by the Mayacamas Mountain Range on the western and northern sides and the Vaca Mountains on the eastern side. Several smaller valleys exist within these two ranges. The floor of the main valley gradually rises from sea level at the southern end to 362 feet above sea level at the northern end in Calistoga at the foot of Mount Saint Helena.
The Oakville and Rutherford American Viticultural Areas (AVAs) lie within a geographical area known as the Rutherford Bench in the center of the valley floor. The soil in the southern end of the valley consists mainly of sediments deposited by earlier advances and retreats of San Pablo Bay while the soil at the northern end of the valley contains a large volume of volcanic lava and ash. Several of the small hills that emerge from the middle of the valley floor near Yountville are indicators of the region's volcanic past.
Several mesoclimates exist within the area due to various weather and geographical influences. The open southern end of the valley floor is cooler during the growing season due to the proximity of San Pablo Bay while the sheltered, closed northern end is often much warmer. The eastern side of the valley tends to be more arid due to the rain shadow caused by the western mountains and hills.
Atlas Peak AVA
Designated an AVA on 21 January, 1992. The Atlas Peak AVA is located within Napa Valley AVA just northeast of the City of Napa. The appellation sits on a higher elevation than most of Napa's wine region which limits the effects of the cool fog coming in from Pacific Ocean.
The westward orientation of most vineyards on the Vaca Mountains also extends the amount of direct sunlight on the grapes. The soil of this AVA is volcanic and very porous which allows it to cool down quickly despite the increased sunlight.
The area has a fairly significant diurnal temperature variation upwards of 30 °F between daytime and night. This contributes to the balance of acidity that grapes from Atlas Peak vineyards are known to have.
Calistoga AVA
The Calistoga AVA was established on 7 December, 2009. It is located in the northern portion of California's Napa Valley AVA.
The appellation is distinguished by its volcanic soil, high temperatures up to 100 °F during the day, and cool nights during the growing season due to breezes from the Russian River, causing the highest diurnal temperature variation in the Napa Valley—up to 50 °F
Despite sharing a name, the Calistoga AVA does not encompass the entirety of the town of Calistoga. The area is noted for its topographical diversity and uniform geology, with bedrock almost exclusively made through volcanic action. The hot days provide color and flavor in the wines, while the cool nights help to maintain acidity and structure.
The appellation abuts the Diamond Mountain District AVA to the south and west, the Saint Helena AVA to the southeast, and the Howell Mountain AVA is a short way to the east.
The name Calistoga dates back to 1857, with the first vine plantings in 1862. Viticultural and winery census data from 1880 list Calistoga as a distinct region separate from Napa.
Chiles Valley AVA
The Chiles Valley District is located in Napa County and is a sub-region within Napa Valley AVA. It was established on February 16, 1999.
The Chiles Valley is nestled in the Vaca Mountains above the northeast side of the Napa Valley. The appellation has a cooler climate than the main Napa Valley floor due to elevations of 600–1,200 feet as well as a cooling breeze from the Pacific Ocean.
The most planted grapes in Chiles Valley are Cabernet Sauvignon, Zinfandel, Chardonnay, and Sauvignon Blanc.
Chiles Valley was named after Joseph Ballinger Chiles, who received the Rancho Catacula Mexican land grant in the 1841. The area was historically a local source for tin, which was mined by residents in the area as of the 1881. Gypsum has also been found in the southern end of the valley.
Coombsville AVA
The Coombsville AVA was established on 13 December, 2011. It is located within the Napa Valley AVA just east of the city of Napa.
The appellation varies from near sea level at the Napa River on the west to 1,900 feet at the ridge of the Vaca Mountain Range. Proximity to San Pablo Bay contributes to the temperate climate of Coombsville. Cooling effects of marine air and fog occur almost daily during the growing season, arriving earlier and lingering longer than in the more northern regions of Napa Valley. Temperatures are less extreme during the winter frost season.
The Coombsville soils are dominated by the volcanic rhyolitic tuff sedimentary rock and lava flows of the Vaca Range on the eastern side of the Napa Valley. Located in the wide alluvial deposits created by the wearing down of the hillsides, the Coombsville soils contain abundant rock, gravel and, in some areas, are layered with volcanic ash deposits from Mount George.
Diamond Mountain District AVA
The Diamond Mountain District AVA was designated on 31 May, 2001. It is located in California's Mayacamas Mountains in the northwest portion of the Napa Valley AVA.
The appellation sits at a higher elevation than most of Napa Valley's wine region, resulting in less cool fog coming in from San Pablo Bay, and more direct exposure to sunlight. The soil of this AVA is volcanic and very porous which allows it to cool down quickly despite the increased sunlight.
The entire AVA is over 400 feet above sea level, which helps to cool it compared to the nearby valley floor appellations. The soil of the Diamond Mountain District is volcanic, including the small bits of volcanic glass that give the area its name.
The AVA is defined by the Napa-Sonoma county line on the west, Petrified Forest Road on the north, the 400 foot line of altitude running parallel to Route 29 on the east, and the Spring Mountain District to the south. This puts the southern part of the city of Calistoga, California in the appellation, with the northern part being in the Calistoga AVA since 2010.
Diamond Mountain District's history as a winegrowing region dates back to 1868, when the first vines were planted by Jacob Schram on a tract of land he purchased on the Napa side of the mountain.
Howell Mountain AVA
Designated an AVA on 29 December, 1983 due to research predominantly done by Bill Smith (formerly of La Jota and later W. H. Smith Wines), Howell Mountain was the first whole sub-appellation within Napa Valley AVA. The AVA is located in the Howell Mountains within the Vaca Range on the northeast side of Napa Valley around the town of Angwin, and overlooks the town of St. Helena. The boundaries of the AVA are dictated by vineyard land located at elevations at least 1,400 feet.
Most vineyards in the Howell Mountain AVA are planted between 1,400 feet and 2,200 feet above sea level, well above the elevations in Napa Valley that are most affected by the cool fog and winds from San Pablo Bay. The mountain does get cool breezes directly from the Pacific Ocean, and the relatively high elevations result in a cooler climate than on the valley floor. The soil in the appellation is volcanic with excellent drainage.
Prior to Prohibition in the United States, the region was widely known for its Zinfandel but in the mid to late 20th century Cabernet Sauvignon became the dominant grape variety.
Oak Knoll District of Napa Valley AVA
The appellation was officially designated an appellation within the Napa Valley AVA on 23 February, 2004. The Oak Knoll District of Napa Valley AVA is located within Napa Valley AVA at the southern end of the valley floor.
The appellation's close proximity to San Pablo Bay results in a climate that is cooler and more moderate than any region in Napa Valley other than the Los Carneros AVA. The AVA has more vines planted to it than any other wholly contained appellation within the Napa Valley.
A wide variety of wine grapes do well in this climate, including varieties not widely grown in other parts of Napa Valley, such as Riesling and Pinot Noir. The district is planted largely to Merlot, Chardonnay and Cabernet Sauvignon, in that order. Oak Knoll District Chardonnay has a reputation for a restrained, delicate style.
Oakville AVA
Oakville AVA was officially declared a sub-appellation of Napa Valley on 1 July, 1993. The Oakville AVA is located within Napa Valley AVA and centered on the town of Oakville. The appellation extends over a flat expanse of well-drained gravel soil between the Vaca and Mayacamas Mountains. Oakville AVA is known for its success with Bordeaux varietals, which have produced wines of rich texture, firm tannins, and notes of mint and herbs.
The soil of the Oakville AVA is the result of sedimentary deposits from the hills that form Napa Valley. The soil is gravelly and sandy, with exceptionally good drainage. The portion of the AVA between State Route 29 and the Silverado Trail is a mix of clay and well-drained sandy loam. Oakville AVA has a warm climate well-suited to wine grape production. Wind and fog arriving from San Pablo Bay can affect the morning and evening hours, but their effects are limited by the intervening Yountville Mounts.
H. W. Crabb planted the first vineyard here in 1868, on 240 acres of land close to the Napa River that he named To Kalon, Greek for "most beautiful". In 1903, the United States Department of Agriculture established an experimental vineyard station in Oakville. Known as "Oakville Station", the vineyard is operated by the University of California at Davis.
There are over 50 wineries located within, or source their grapes from vineyards in, the Oakville AVA. Many are small, boutique wineries (like Harlan Estate, Screaming Eagle and Spoto Wines) with limited production.
Mt. Veeder AVA
Designated an AVA on 19 February, 1990. Mount Veeder AVA is located within Napa Valley AVA among the Mayacamas Mountains. The boundaries of this appellation include 25 sq mi with 1,000 acres planted on thin volcanic sedimentary soil. Many vineyards are found on the steep mountain face some as steep as 30°. The steepness of the angle gives the vineyards benefits of more direct sunlight and better drainage.
The unique sense of place, or terroir of Mount Veeder AVA produces wines that are typically powerful in structure - depending on how they are made and how the vines are tended. For example, Cabernet Sauvignon grown on the mountain commonly shows "briary" flavors, moderate to bold tannins and herbal, floral aromatics. With the increasing interest in wine in America, wines grown in sub appellation AVA's such as Mount Veeder are gaining recognition for their unique sense of terroir.
Wild Horse Valley AVA
Designated an AVA on 29 November, 1988. The Wild Horse Valley AVA has borders that overlap both Napa County and Solano County and is partially contained within the Napa Valley AVA. The appellation's southerly location results in more hours of sunshine than other locations in Napa Valley or nearby Green Valley. The proximity to San Pablo Bay results in a cooler climate, making Wild Horse Valley attractive for the cultivation of grapes like Pinot Noir.
The Wild Horse Valley AVA features two distinct subregions. To the west, the area is cooled by San Pablo Bay, although the elevation keeps the area above the fog line. The eastern half, being protected by the slope of the ground, is much warmer. The soil type is generally volcanic throughout the entire AVA.
Grapes were first planted in the area in the 1880s. The current vineyard plantings date back to 1980, with commercial production starting in 1985.
Yountville AVA
Designated an AVA on 18 March, 1999. The Yountville AVA is located within Napa Valley AVA and centered on the town Yountville.
The town's founder George Calvert Yount planted the first vineyard in this area around 1836. Yountville AVA is one of the coolest wine regions in Napa Valley, which helps contribute to a long growing season.
The area is particularly known for its very tannic Cabernet Sauvignon varietal wines that have the capability of aging well in the bottle.
Spring Mountain District AVA
Designated an AVA on 12 May, 1993. The Spring Mountain District AVA is located in the Napa Valley AVA. Spring Mountain District AVA was officially established as an American Viticulture Area in 1993. Encompassed within its bounds are about 8,600 acres, of which about 1,000 acres are planted to vineyards.
Given the small crop yields on hillsides, the region represents less than 2% of Napa Valley wine. About 90% of the wine produced in the Spring Mountain District AVA is red. The predominating grape variety is Cabernet Sauvignon followed by Merlot. In addition to the other Bordelaise grape varieties of Cabernet Franc, Petit Verdot and Malbec, a few sites favor and support small plantings of Zinfandel, Syrah, Petite Sirah and on the coolest sites, even a little Pinot Noir. Of the whites over half is Chardonnay. The other significant plantings of white grapes in the AVA are Sauvignon Blanc and White Riesling.
The appellation sits on steep terraces of the Mayacamas Mountains that separate Napa Valley from Sonoma Valley and the Santa Rosa Plain. It lies in a northwestern portion of the Napa Valley above and behind the town of Saint Helena. The boundaries of the appellation extend from the top of the ridgeline on the western edge, tracing the Sonoma/Napa County border. From the ridgeline the boundaries extend down to the 400 feet contour line at the eastern base of the hillside. The southern boundary is Sulphur Creek and one of its tributaries, while the northern boundary is Ritchie Creek. Elevations range from 400 feet to 2,600 feet. The region has a predominantly eastern exposure.
Local topography and regional weather patterns make the Spring Mountain District the coolest and wettest appellation within the Napa Valley. These same factors create a diurnal fluctuation in temperature in the summertime that differs from other regions of the Napa Valley. Spring Mountain District AVA receives 10 inches to 15 inches more annual rainfall than the Napa Valley floor or the eastern slopes of the valley. The overall effect of this is moderately warm peak daily temperatures and moderately warm nighttime temperatures which keeps sugar accumulation in the berry in pace with flavor development.
Soil depths vary, but tend to be deeper than in nearby mountain terrain and shallower than on the valley floor. The region contains mostly residual upland soils with only a few areas of alluvial soils at the lower elevations. The soils are derived almost equally from Franciscan sedimentary rocks (sandstone and conglomerates) and Sonoma volcanic formations which are predominantly composed of Andesite.
St. Helena AVA
St. Helena AVA is located within Napa Valley, centered in and around the town of St. Helena. It was established on September 10, 1995.
The appellation covers 9,060 acres along the flat narrow land towards the northern end of the valley between the Vaca and Mayacamas Mountains. Its soil is mostly loam with good water retention and varying amounts of gravel.
The area has a Warm-summer Mediterranean climate, and is somewhat hotter than nearby wine growing regions with summer temperatures that often reach the mid 90s Fahrenheit. It receives approximately 40 inches of rainfall per year.
The region is known for its red wines, including Zinfandel, Petite Sirah and Pinot Noir, although white wines are also produced there such as Chardonnay. Its terroir is particularly well suited to Bordeaux, particularly Sauvignon Blanc. St. Helena's Cabernet Sauvignon is noted for its quality.
In 1860, George Belden Crane planted Mission vines in St. Helena, and the vineyard produced its first wine in 1862. By 1874, the vineyard had produced 500,000 gallons of wine annually. Charles Krug, one of the pioneers of Napa Valley winemaking, founded his winery in 1861 in the St. Helena district.
The AVA hosts more than 93 wineries with about 6,800 acres (2,800 ha) cultivated.
Stags Leap District AVA
Designated an AVA on 26 January, 1989. The Stags Leap District AVA is located within the Napa Valley AVA, 6 miles north of the City of Napa. The Stags Leap District was the first appellation to be designated an AVA based on the unique terroir characteristics of its soil. The soil of this region include loam and clay sediments from the Napa River and volcanic soil deposits left over from erosion of the Vaca Mountains. Stags Leap District is particularly known for its Cabernet Sauvignon.
In 1976 at the Judgment of Paris wine tasting, the 1973 Stag's Leap Wine Cellars Cabernet (from the area that would become this AVA) won first place in the red wine category, beating out classic Bordeaux estates.
Grapes were planted in the area that would become the Stags Leap District as early as the 1870s, with the first winery in the area being founded in 1878. Nathan Fay planted the first Cabernet Sauvignon in the area in 1961.
One of the leading forces in the region is Stags Leap District Winery Association which aims to promote the wines of the AVA and host an annual day-long event called “Vineyard to Vintner” which allows consumers the opportunity to interact with wineries and taste the regions wine.
Rutherford AVA
Rutherford AVA was officially declared a sub-appellation of Napa Valley on 1 July, 1993. The Rutherford AVA is located within Napa Valley AVA and centered on the town of Rutherford.
The area is known for its unique terroir particularly with its Cabernet Sauvignon. The well-drained soil of this area is composition of gravel, loam and sand with volcanic deposits and marine sediments from the Franciscan Assemblage.
The appellation accounts for only 6,650 acres in the center of Napa Valley but has been home to some of the regions most historic and world-renowned wineries such as Beaulieu Vineyards, Rutherford Hill, Raymond Vineyards, and Inglenook Winery.
Los Carneros AVA
Los Carneros AVA (also known as Carneros AVA) received its AVA status on 17 August, 1983. The Carneros area was the first wine region in California to be defined by its climate characteristics rather than its political boundaries. Los Carneros AVA includes parts of both Sonoma and Napa counties. It is located north of San Pablo Bay.
The proximity to the cool fog and breezes from the bay makes the climate in Los Carneros AVA cooler and more moderate than the wine regions farther north in Napa Valley and Sonoma Valley. The cooler climate has made Los Carneros attractive for the cultivation of cooler climate varietals like Pinot Noir and Chardonnay. Many of the grapes grown in Los Carneros are used for sparkling wine production.
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.
The soils of the Carneros region are predominantly clay and very thin and shallow (approximately 3 feet deep), 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.
“In wine, there’s truth.”