From the Food & Wine website:

Napa Valley & The Sierra Foothills, California: Helen Keplinger

One characteristic great winemakers share is that they understand potential. Helen Keplinger, for instance, is making extraordinary wines in very unassuming regions—the steep, rocky vineyards of California’s Amador and El Dorado counties in the Sierra Foothills, mostly known for affordable Zinfandels.

How does someone recognize that kind of hidden potential? In Keplinger’s case, it stems from time spent making other world-class reds (for Napa Valley’s Bryant Family Vineyards), as well as familiarity with terroirs like the Priorat and its similarly stony vineyards (she was a winemaker there). Or, it just might be a love of rocks. As she says, “If you like rocks the way I do, these places are insanely compelling.” Either way, her vision is clear in wines like the 2010 Keplinger Lithic ($60), a mineral-rich, layered blend of Grenache, Syrah and Mourvèdre; it’s the kind of wine that may someday help redefine a whole region.