(TheDrinksBusiness) - Preparations for Premiere Napa Valley, the main Napa Vintner trade event have started, and Catherine Seda explains the elaborate process involved. In early December, winemakers from top Napa Valley wineries could be seen entering the Napa Vintners’ trade association offices on Library Lane in St. Helena and departing an hour or two later with black teeth and a slip of paper in their hands. Following day a different group of winemakers repeated this ritual; same black teeth, same slip of paper. Had you caught this activity the week before, the only change was that the pearly whites stayed white.