San Antonio Valley is a small wine region in Chile, located to the west of the capital, Santiago. A new addition to the Chilean national vineyard, the region stands out as being able to produce quality Pinot Noir along with internationally respected white wines, including Sauvignon Blanc and Chardonnay.
The province for which the valley is named surrounds the city of San Antonio, 55 miles (90km) west of central Santiago and just south of Casablanca Valley. Vineyards lie on the rolling hills that characterize the region, often within 20 miles (32km) of the Pacific Ocean that forms San Antonio's western edge. The Leyda Valley, within San Antonio Province, is one of Chile's up-and-coming wine districts.
As in Casablanca Valley, the viticulture in San Antonio Valley is heavily influenced by the effects of the ocean. Cool morning mists and spring frosts are more associated with the Napa Valley and Bordeaux than they are with Chilean wine regions, but the cold Humboldt Current, which flows up the west coast of Chile, brings exactly these conditions to San Antonio Valley. This oceanic influence is largely responsible for making viticulture possible here, as the valley is located at latitude 33°S – much closer to the Equator than any European vineyard.
The cooler conditions during the day and the significant drop in temperature at night lead to an extended growing season and a slower ripening period, meaning that the San Antonio Valley can produce quality Pinot Noir and Chardonnay balanced in sugar and acids, as well as aromatic white varieties.
The soils in the valley are largely granitic, with a topsoil of clay. These poor, well-drained soils are excellent for viticulture: vines are forced to grow deep root systems in search of nutrients and water, leading to healthy plants that produce high-quality grapes.
The moderate rainfall, concentrated in the winter months, is not enough to sustain the vines and some irrigation is necessary. But without an abundant source of water, save for the Maipo River some way to the south, a five-mile-long (8-km) pipeline has been constructed to bring water from there to the Leyda Valley in particular. The capacity of this pipe is limited, however, which has restricted viticultural expansion.
San Antonio valley is small when compared to the sprawling regions at the center of Chilean wine growing. Like the Aconcagua Valley to the north-east, it is home to a limited number of producers. In this case, they are newcomers – specialists capitalising on the unusual terroir – rather than larger wineries focused on mass production.
San Antonio Valley should not be confused with the San Antonio Valley AVA in Monterey County, California.