Theorem Vineyards’ debut vintage was in 2012. Tucked into the hillside north of Diamond Mountain in Calistoga, Theorem was founded by the husband and wife team of Kisha and Jason Itkin. Kisha is company president and the vineyard’s name is a reference to Jason’s work as a trial lawyer. The 20 acres of vineyards are at 1,100 feet above sea level, and the estate grows primarily Cabernet Sauvignon and a little Merlot. Thomas Rivers Brown is winemaker. The wines are generally available via a mailing list.