Their first winemaker developed a drinking problem, and when John Shafer finally convinced his son, by then a graduate of UC Davis's viticulture program, to take over as winemaker, the cellar was in abominable shape, full of mold, spoiled wine and a bacterial taint called Brettanomyces, which spoiled their 1981 vintage.
WSJ: The Near-Accidental Brilliance of Shafer Vineyards