Page "Scotch whisky" Paragraph 61

Historically, casks previously used for sherry were used ( as barrels are expensive, and there was a ready market for used sherry butts ).

Today, the casks used are typically sherry or bourbon casks, but with many now coming from northern France with its huge supply of aged white oak casks used in both white and red wine production.

Sometimes other varieties such as port, Cognac, Madeira, calvados, beer, and Bordeaux wine are used.

American whiskey production is a nearly inexhaustible generator of used barrels, due to a United States regulation requiring the use of new, freshly charred oak barrels in the maturation of bourbon and many other types of whisky.