When first planting grapes in the Napa Valley, varieties were planted in somewhat random patchwork patterns. But as winemaking became more of an art, vintners discovered the benefits of matching certain grapes to appropriate microclimates and soils, thus regions have emerged that imprint recognizable characteristics on the grapes grown within them. All this helps the consumer to not only discover what they like, but identify and find it more easily.
Since Napa Valley itself is an appellation, it helps to know the 15 sub-appellations as certified by the American Viticultural Area (AVA for short). Each offers distinctive characteristics that affect not only the grape, but also the resulting wines.
Atlas Peak AVA: The mountain-influenced climate gives Cabernet Sauvignons added acidity, while influencing Chardonnays with crisp, distinctive pear-mineral flavors.
Calistoga AVA: Warmer to downright hot temperatures along with marine air from the Northwest favors Cabernet Sauvignons, Zinfandels, Syrahs and Petite Sirahs.
Chiles Valley District AVA: Later harvests add lush yet firm texture and distinctive blackberry flavors to Cabernet Sauvignons, Merlots and Cabernet Francs; while Merlots are distinguished by black cherry flavors with hints of cocoa.
Diamond Mountain District AVA: Moderately warm temperatures give Cabernet Sauvignons and Cabernet Francs firm structure with strong blackcurrant mineral and cedary flavors. Chardonnays are distinguished by green apple-peach aromas.
Howell Mountain AVA: Afternoon sun influences Cabernet Sauvignons, Merlots and Zinfandels with firm blackberry-currant flavors and excellent acidity for aging. Chardonnays reveal more citrus and stone fruit flavors.
Los Carneros AVA: Cooler, marine-influenced winds from San Pablo Bay provide Chardonnays with pear-apple and spice flavors, Merlots with sleek structure and Pinot Noirs with earthy cherry-cinnamon spice flavors.
Mount Veeder AVA: Vineyards above the fog line bestow Cabernet Sauvignons, Merlots and Zinfandels with firm, tannic structures and earth-berry aromas, while adding apple and citrus flavors along with good acidity to Chardonnays.
Oak Knoll District of Napa Valley AVA: Marine air and fog provide Merlots and Cabernet Sauvignons with cassis, tobacco and spice flavors typical to Bordeaux-style reds, while Chardonnays feature crisp, apple mineral notes with fine acidity.
Oakville AVA: Moderately warm temperatures result in Cabernet Sauvignons and Merlots with ripe currant and mint flavors; along with Sauvignon Blancs that are full, steely and very fleshy.
Rutherford AVA: Early morning fog gives way to warm temperatures that provide Cabernet Sauvignons, Merlots, Cabernet Francs and Zinfandels with intense cherry and mineral aromas along with supple tannins for extended aging.
Spring Mountain District AVA: Fairly cool nights and higher elevations result in Cabernet Sauvignons, Merlots and Zinfandels with powerful blackberry-currant flavors and excellent agility for aging while Chardonnays exhibit less fruity, more citrus and stone fruit flavors.
St. Helena AVA: Mid summer temperature peaks of 90+ degrees bestow Cabernet Francs, Cabernet Sauvignons and Merlots with deep, ripe and often jammy flavors.
Stags Leap District AVA: Moderate warmth along with afternoon marine winds distinguish Cabernet Sauvignons, Merlots and Sangioveses with finely perfumed cherry and red berry flavors while Chardonnays and Sauvignon Blancs exhibit excellent citrus and apple flavors.
Wild Horse Valley AVA: Warmth that’s moderated by both altitude and winds result in Cabernet Sauvignons and Sangioveses with bright berry and cherry fruit and provide Chardonnays with distinctive pear-mineral flavors and bright acidity.
Yountville AVA: Fog and a cooler marine influence provide Cabernet Sauvignons and Merlots with ripe, violety aromas and firm tannins.