Cornerstone Cellars was founded by two physicians from Memphis, Tennessee, Michael Dragutsky and David Sloas, and released its first commercial vintage in 1991. Over more than three decades the winery has built its reputation on Napa Valley Cabernet Sauvignon, sourced from respected vineyards around the valley, along with other Bordeaux-style reds. Kari Auringer was the winemaker through the 2024 vintage. The winery has changed hands recently: in 2024 Assemblage Retail Group, owned by Third Leaf, bought Cornerstone Cellars. In 2026 the winery opened the Yount Room in Yountville as its tasting space, putting it in one of the most visited towns in Napa Valley, steps from many of the valley's best restaurants. For HeyVino readers, Cornerstone is a long-running Napa label with a convenient Yountville tasting room, and its wines appear in both retail and direct offers.