Napa Valley may be a giant in the world of wine, but its actual wine production is relatively small. The floor of Napa Valley is only 30 miles long and 5 miles across with 46,000 acres under cultivation all over Napa. To put that in context, the wine growing region of Bordeaux is eight times the size of Napa. In fact, Napa only represents only 4% of wine grapes grown in California and only 0.4% of the world’s wine production. Napa’s outsize influence on the wine world is due in part to these limits on production as well as the benefits of a near-perfect climate.
Climate is the most important factor in making a first-rate viticultural area. Napa Valley enjoys an ideal Mediterranean climate created by the combined influences of San Pablo Bay and the hills of the North Coast Ranges. Morning fog rolls off the bay and the hills force it deep inland, up into the valley. Without the fog’s cooling influence, the valley would be substantially warmer than it is, making it nearly impossible to produce wines with the kind of structure and balance needed to compete with Old World wines.
The fog doesn’t make it above the valley floor, however, leaving higher-elevation vineyards to rely on the cooler altitude to keep their vines in balance. These hillside vineyards tend to be more dry and windy than their valley neighbors. The Carneros sub-AVA, straddling both Napa and Sonoma, sees the brunt of the cool air from San Pablo Bay, making it an atypical Napa style.
Napa Valley is home to a rich diversity of soil types representing 50% of the world’s soil orders in just 789 square miles. Soil composition has a great impact on the character of the grapes grown and Napa Valley grape growers must take this into account when deciding which varieties to plant. Just as the climate can vary from site to site, the very soil presents a volatile challenge to the winegrower.
Soil on the valley floor tends to be deeper and more fertile. The grapes grown here are fast-growing and vigorous, so the crop must be tightly managed to ensure concentrated grapes. On the rocky, free-draining hillsides, the vine has to struggle to survive and naturally sets a smaller crop, producing highly concentrated color and flavors.
Grapes and Wine
More than 34 different wine grape varieties are grown in Napa Valley. Decades ago, Robert Mondavi pioneered the practice of varietal labeling, making wine grapes household names all over the world. Unlike wines from France, where the wine style is normally denoted by the region or estate where the wine was grown or produced, varietal labeling takes the name of the grape variety as the name of the wine style. This straightforward method, while being thoroughly American, also says something about what Napa winemakers thought about the importance of their agricultural produce.
Cabernet Sauvignon is the undisputed Queen of Napa Valley, being the most widely planted grape in almost all of the valley’s sub-regions. In Carneros, however, the cool microclimate is better suited to Pinot Noir and Chardonnay. Merlot Since its fall from favor in the 1990s thanks to the movie Sideways, Merlot is now used mostly in blends. Zinfandel remains a significant Napa grape with a long history in the region although it represents only a small proportion of the valley’s vineyard area. While outnumbered by reds, white wines play a valuable supporting role, the most prominent being Sauvignon Blanc and Chardonnay.
Napa Valley Wineries
Here at Prime Cellar, we’re proud to represent some fabulous Napa Valley wineries in our inventory. Please check out a sampling below and discover for yourself the history and delight of Napa Valley.