PlumpJack Winery is a boutique winery in Oakville, California, specializing in premium Cabernet Sauvignon wines. PlumpJack was the first winery in Napa Valley to use screwcaps as a wine closure on fine wines. The winery is one of several businesses operated by the PlumpJack Group. The name of the company is inspired by "the roguish spirit of Shakespeare's Sir John Falstaff (Henry IV), dubbed Plump... Wikipedia