In Europe, cognac is protected by an origin appellation, which means that only brandy produced in Cognac from certain grapes in a certain way may be labeled as cognac. This protects the integrity of this often-imitated spirit, and provides some protection to European buyers who might be confused. Outside of Europe, many companies claim to produce cognac, which can be confusing and frustrating for consumers. In the United States especially, some people are under the false impression that all French brandy is known as cognac; in fact, numerous brandies are produced in France, including Armagnac, another famous and protected brandy. By law, cognac must contain Ugni Blanc, Folle Blanche, or Colombard grapes, although other grapes may be added. These grapes are pressed and fermented to yield a very dry, somewhat bland white wine which is subjected to a double distillation process, yielding raw cognac which is routed into oak barrels for aging. The stills used to produce traditional cognac are made from copper, incidentally. True cognac must be aged for at least three years. This adds significantly to the cost of the final product, as the spirit must be stored in temperature controlled environments while it ages, and the barrels must be cared for by trained professionals. Cognac producers also experience product loss through evaporation as the spirit ages. After three years, the cognac is drinkable, though very young, with a raw, intense flavor.