The finest balsamic vinegar is made from the must of a white wine grape, the Trebbiano. It is cooked down and then aged in barrels made of different kinds of aromatic woods, such as chestnut, cherry and mulberry, which impart their unique flavors to the vinegar. Many homes in the countryside of Emilia-Romagna have an acetaia, an attic room devoted to storing the vinegar barrels. At least 12 years of aging are required to make genuine aceto balsamico, and only the finest specimens are permitted to be called aceto balsamico tradizionale di Modena. These artisanally made vinegars are quite expensive and are meant to be drizzled over foods, such as fresh strawberries or Parmigiano-Reggiano, or used sparingly as a condiment. The very finest are sometimes sipped as a cordial. At one time it was believed that balsamic vinegar could alleviate some of the pain of childbirth, so small amounts were given to expectant mothers during delivery.For cooking purposes, the less expensive commercially made balsamic vinegars will suffice. They add a pleasant sweet-tart lift to sauces and soups and form a lovely brown glaze on grilled meats and poultry.