Winter is at the base of Spring Mountain in St. Helena. It was started in 2004 by Rob Winter, a Napa Valley custom-home builder who decided to make his own wine. He hired Mike Hirby as winemaker. Trained as a sommelier, Hirby moved to Napa Valley and became part of the winemaking team at Behrens & Hitchcock and Sherwin Family Vineyards, among others. Winter makes just one wine, a Cabernet Sauvignon produced mostly from estate grapes but also from select Napa vineyards. Winter has earned ratings in the mid to high-90s.