The first vines were planted in San Diego, CA by Spanish missionaries in the late 1700s. Commercial winemaking began in the 1820s. The Gold Rush of 1849 brought vineyards closer to the Sierra Foothills so the miners wouldn't have to travel as far to meet their daily needs. In the 1850s, Agostin Haraszthy brought around 300 different types of European varieties to California, leading to the birth of California's modern wine industry.
As people sprawled around the San Francisco Bay area after the Gold Rush, vine plantings increased substantially, and Sonoma and Napa began to take off. While Europe suffered from phylloxera issues in the 1870s and 1880s, California wineries experienced a boom. People began spreading further and planting vineyards up and down the state.
Prohibition, not surprisingly, had a major impact on the California wine industry, and in the 1920s there was a decline in production. However, a few forward thinking wineries pushed through this period by selling bulk grapes and grape juice along with yeast and clear instructions not to mix the ingredients in a very precise manner or else wine would result. And some wineries just kept selling to churches, since church-sponsored drinking wasn't evil.
Key Regions (North to South)
Mendocino - Known for Cabernet Sauvignon, Sauvignon Blanc, Petite Sirah and Zinfandel. Home to the smaller region of Anderson Valley where Chardonnay and Pinot Noir are grown to produce traditional method sparkling wines. The climate is similar in many ways to that of Champagne, and these are arguably among the best sparkling wines produced in the US.
Sonoma - One of California's largest and most important wine regions, it rivals neighboring Napa in both fame and quality. A key region for Cabernet Sauvignon, Chardonnay, Pinot Noir, Sauvignon Blanc, and Zinfandel.
Napa - California's most famous (and most expensive) wine-making region. The diversity in climate, soil and aspect in Napa creates ideal growing conditions for many grape varieties with international demand. Known primarliy for rich, full-bodied Cabernet Sauvignon, but also produces high quality Chardonnay, Merlot, Sauvignon Blanc, Syrah and Zinfandel.
Monterey - One of California's driest regions, where many of the vineyards depend on irrigation from the underground Salinas River. Known for Chardonnay, Pinot Blanc, Pinot Noir and, to a lesser extent, Cabernet Sauvignon and Riesling.
San Luis Obispo - Home to one of the hottest (Paso Robles) and one of the coolest (Arroyo Grande Valley) AVAs in California. Known for Cabernet Sauvignon, Pinot Noir, Sauvignon Blanc, Syrah and Zinfandel.
Santa Barbara - The southernmost part of California's Central Coast wine region. While the town itself has almost subtropical conditions, the vineyards along the Pacific Coast get so much fog that it is among the coolest wine regions in the state. Known for Chardonnay, Pinot Noir and Sauvignon Blanc, and to a lesser extent Cabernet Franc, Cabernet Sauvignon and Merlot.
Types of Wines
The most prominent type of wine produced in California is the varietal wine, which is a table wine that lists a single variety of grape on the label. Aside from varietal wines, California produces just about every other type of wine available in the rest of the world; inexpensive bulk wines, sparkling wines, late-harvest wines and fortified wines.
It is important to note that in the US the type of wine is determined by alcohol content, and is used for tax purposes rather than a measure of quality. Any wine with alcoholic strength below 14% is considered a "table wine" and anything over 14% is a "dessert" wine. This means that many red wines produced in California are technically dessert wines even though they have no residual sugar in them. These bottles are not required to be labeled as dessert wines, as the majority of them (Cabernet Sauvignon, Pinot Noir, Syrah, Zinfandel) are dry table wines with no sugar. The government term for "dessert" wine is solely for taxation purposes, while when wine makers refer to dessert wines, they typically mean a sweeter wine.
Prominent Grape Varieties
Most of the wines produced in California are made of the popular international or European grape varieties, though small vineyards with unique and delicious varieties can be found scattered throughout the state.
As everyone already knows, California is perfect, sunny and mild all the time. How they manage to get any wine made after a long day of surfing is anyone's guess.
But the reality is that the climate in California is rather varied due to geographic influences. Fog created by offshore currents is a constant problem up and down the coastline, interfering with grapes' ability to get enough sunlight to ripen. However, various pockets of land (as pictured in the map above) do get some ideal temperatures and conditions. Despite being close to cold and foggy San Francisco, Napa is protected by mountain ranges and is one of the warmest and driest regions in the state. Rainfall is somewhat regular, falling mostly in the winter months. Winter is relatively mild throughout the state, creating very small risk of severe cold damage to the vines.
Spring frosts are one of the largest climatic issues in California, as frost can kill young buds on the vine and ruin the upcoming crop. Many tools are used to either move cold pockets of air or shield the grapes from the frost. In Napa, giant fans such as those in the video above are commonly used for pushing cold air away from low areas.
The geography of California is very varied, so it is difficult to give a generic overview (particularly since the areas under vine run about 600 miles from north to south and another 135 miles east to west). The soil in California is made of many different things due to the coming together of the Pacific tectonic plate and the North American tectonic plate (the cause of all those lovely earthquakes).
In 1983 the federal government began setting legal boundaries for defined wine regions called American Viticultural Areas (AVAs). These AVAs can be used on labels, and vary from broad (California) to specific (Oak Knoll District - which is within the AVA of Napa, which is within the AVA of the North Coast, which is within the AVA of California). While AVAs are supposed to be set up in accordance with specific geographich conditions, they are largely based on political and commercial reasons. A prime example is within the AVA of Napa. The various soil types in Napa generally run in veins from north to south, so it would make sense for the smaller AVAs to follow these veins. However, most of the AVAs run east to west along town boundaries and winery property lines, crossing different soil types and different climatic conditions.
Viticulture and Wine Making
California is often at the forefront of vineyard management and winemaking technologies. The University of California at Davis is home to one of the world's best research facilities, particularly when it comes to viticulture and oenology.
Wineries range from massive conglomerates pumping out millions of gallons to tiny boutique wineries producing a mere handful of cases each year. The vineyard techniques vary from the latest mechanical processes to harvesting by hand, and from massive chemical use to totally organic practices. And it is a mistake to assume that all large wineries use chemicals and all small ones do not.
Practices are similarly varied inside the wineries. Without centuries of tradition as a guiding principal, most wine makers follow a largely scientific approach taught at UC Davis, carefully measuring, monitoring and controlling the whole process of fermentation. Many others treat wine making as an art form and combine modern techniques with classical ones, innovating and learning every year.