Paso Robles is a large winegrowing area at the southern end of California's Central Coast region. At 666,500 acres (270,000ha) the official Paso Robles AVA is among California's very largest; it effectively covers the northern half of San Luis Obispo County. Paso Robles wines are typified by rich, ripe reds based on warm-climate varieties such as Zinfandel, Cabernet Sauvignon, Merlot and the Rhone Valley trio Grenache, Syrah and Mourvedre.
In 2013, proposals to create specific sub-AVAs in Paso Robles were ratified and the region was divided into 11 new designated appellations. Previously, Paso Robles had been the largest AVA in California to remain un-subdivided; in contrast, it is three times the size of the Napa Valley viticultural area, which has 16 individual designated sub-appellations. The sub-division recognizes the diverse growing regions in Paso Robles, with altitudes ranging from 700 to 2,400 feet (213-730m), a range of soils, and varying degrees of regional influence of the marine effects of the Pacific Ocean.
© Wikimedia/SD Dirk
Viticulture here dates back to the late 18th Century, when the first wine grapes (most likely of the Mission variety) were planted by Spanish missionaries. The first commercial winery was established in 1882, incorporating the region's earlist Zinfandel vines. Today, wine from Paso Robles are made from a wide range of grapes. The majority are made from the warm-climate varieties mentioned above, but varieties such as Pinot Noir and Chardonnay are also found, mostly in the very coolest vineyards of the region.
The AVA's northern limit is marked by the county line with Monterey County, from where it stretches southwards along the Salinas river valley for about 35 miles (55km). It stops just short of San Luis Obispo city, just on the other side of which lies the Edna Valley and Arroyo Grande Valley AVAs. Its western edge is defined by the Santa Lucia coastal mountains, beyond which lies the Pacific coastline.
Despite its proximity to the Pacific Ocean, Paso Robles' climate is remarkably warm and continental. This is due largely to to the hills that lie between the main vineyard areas and the coast. These shield the area from climate-moderating coastal influences, meaning hot days and cool nights almost everywhere within the AVA. The region is not entirely bereft of refreshing coastal breezes, however, thanks to the "Templeton Gap". This is not a single gap per se, but a series of narrow river valleys that bisect the Santa Lucia range, collectively allowing Paso Robles to "breathe" cool, coastal air in the afternoon and early evening. Regions vary in climate largely due to their proximity to the Templeton Gap and their relationship to the shielding effects of the Santa Lucia range and the Temblor Range to the east.
The scale of soil diversity throughout Paso Robles is tremendous and it is not unusual to have several types within one vineyard site. Primarily, bedrock is composed of weathered granite, volcanic and marine sedimentary rocks overlayed with shallow combinations of sandstone, mudstone or calcareous shales. This is a stark comparison to the deep, fertile soils predominately found elsewhere in California.