The Consorzio in charge of Vino Nobile di Montepulciano has proposed controversial changes to the rules for this famous southern Tuscan wine. Currently Vino Nobile, the very first wine ever elevated to the superior status of DOCG in 1980, must consist of a minimum of 70% of Sangiovese, or Prugnolo Gentile as it is known here, with the balance made up of a maximum of 20% of the indigenous Canaiolo and a maximum of 20% of 'authorised grape varieties'. This rather cryptic phrase already allows for the international grape varieties, first and foremost Cabernet Sauvignon, Merlot and, increasingly, Syrah to put their stamp on the wines, but...