California is the largest and most important wine region in the United States. Occupying the southern two-thirds of the country's west coast (Oregon and Washington make up the rest), it spans almost ten degrees of latitude and 850 miles (1370km) of coastline. With mountains, valleys, plains and plateaux, the state's topography is as complex as its climate, offering winegrowers a bewildering choice of terroir.
Although Californian wines rose to global renown only in the past few decades (notably after the Paris Judgment of 1976), the state's viticultural history dates back more than 150 years. The first vines were planted here in the 19th century, as European settlers and missionaries made their way up and down the west coast. They brought with them the Mission grape – the vinifera variety also instrumental in establishing viniculture in Central and South America. Although very few Mission vines are to be found in California today, it remains a cornerstone of Californian wine.
The first half of the 20th century brought war, Prohibition and the Great Depression to the United States, collectively suffocating the nation's once-burgeoning wine industry. It wasn't until the significant social, cultural and economic developments that followed World War 2 that things began to change. In the 1970s, the leading lights of the Californian wine industry brought about renewed winemaking passion in other US states, ultimately sparking the national wine renaissance. This period saw a proliferation of new, small-scale wineries throughout the country and the upscaling of longer-established operations and created momentum that has continued into the 21st century.
Today, California hosts some of the world's largest wine companies, but it is also home to a number of boutique wineries, some of which attract astronomical prices for their cult wines. Whether through mass production or single-vineyard artisanal winemaking, California produces 90% of American-made wine and supplies more than 60% of all wine consumed in the country, shipping a record 211.9 million cases in 2011.
The principal varieties grown in California are Cabernet Sauvignon and Chardonnay. A wide range of traditional European (Vitis vinifera) vines also flourish, grafted to hardy, phylloxera-resistant American rootstocks. Less well known are American/European hybrids producing wines mainly for local consumption. Many French Champagne houses have set up wineries in California. The most famous examples are Moet & Chandon's Domaine Chandon, Taittinger's Domaine Carneros, Louis Roederer's Roederer Estate in the Anderson Valley and Mumm Napa in the Napa Valley.
Soils and climates vary substantially throughout California, according to a complex combination of altitude, latitude and proximity to the cool waters of the Pacific Ocean. As a rule of thumb, the more mountains there are between a vineyard and the Pacific, the less it benefits from the cooling effects of a maritime climate. In summer, the cold inshore waters of the Pacific help to create a fog bank just off the coast. As the inland air warms and rises, cold fog is sucked in to fill the space. In extreme cases, fog has been known to travel as far as 100 miles (160km) inland, cooling and refreshing the land as it goes.
Generally, the cooler regions closer to the coast are better suited to Pinot Noir and Chardonnay, while further inland – where the climate is much hotter – some of California’s most-famous Cabernet Sauvignon wines are grown. Zinfandel produces some outstanding examples throughout this important region.
To sum up the complex climatology, topography and geology of such a large area is impossible without losing the subtleties that make one wine different from the next and that ultimately make wine such an interesting topic. For specific information on each of California's wine regions and AVAs, please use the links below.