While the Mission grape variety dominated the early plantings, another variety - quite different - was imported from somewhere in the Adriatic region, and the wine made from this grape became known as Zinfandel.
Ask Sierra Foothills winemakers what gives the area's wines their unusual robust taste, and they'll tell you, "It's the soil."
Most of the vineyards at the 2,000-foot elevation are set in a soil made of decomposed granite, a product of erosion from the Sierra Nevada range. This granitic soil is typical of the Shenandoah Valley in Amador County, around Murphys in Calaveras County, and in the Fair Play/Somerset area in El Dorado County.
At the higher El Dorado elevations (close to 3,000 feet), the soil is composed of finely crushed volcanic rock, thrown up by volcanoes in the Lake Tahoe area some 10 million years ago. Lava Cap Winery takes its name from this soil.
Both types of soil have good drainage and very few nutrients, making the vines send their roots deep into the ground to hunt for food and water. The substantial root structure provides the grapes with the flavors of the specific vineyard site.
Some of the vineyards are dry farmed, with no summertime irrigation. These vines bask in the intense sunshine, and produce grapes with skins that have a deep blue/black color.
Stressed vines produce richer, more deeply flavored wines, and in the Sierra Foothills, that means mostly Zinfandel, Cabernet Sauvignon and Syrah.