What makes a wine distinctive is the goUt du terroir, or the taste of the land-plus the personality and passion of the wine maker who lovingly adds his own liqueur de dosage or secret ingredient to each bottle. Here is a vintner's month-by-month account of one vintage at the Iron Horse vineyard located in the hills of Sonoma County in California. Author and wife of Iron Horse's wine-maker, Joy Sterling, fascinates with her account of the commitment involved in producing a premium wine.