For three years in the late 70s, legendary Champagne winemaker, Guy Devaux, employed Turrentine Brokerage in a secret project to sample Pinot Noir, Chardonnay and Pinot Blanc grapes from various regions of California and Oregon for the production of luxury class sparkling wine. This complicated and fascinating project eventually became Mumm Napa Valley. After the winery was built and had finished its first crush, Guy invited my wife and I to a dinner at the…