Barrel for at least two years in new, charred oak containers. Other forms of whisky aged in used barrels cannot be called "straight". International laws require any whisky bearing the label "Scotch" to be distilled and matured in Scotland for a minimum of three years and one day in oak casks. By Canadian law, Canadian whiskies must "be aged in small wood for not less than three years", and "small wood" is defined as a wood barrel not exceeding capacity. Since the U.S. law requires the use of new barrels for several popular types of whisky, which is not typically considered
Barrel necessary elsewhere, whisky made elsewhere is usually aged in used barrels that previously contained American whisky (usually bourbon whisky). The typical bourbon barrel is in size, which is thus the "de facto" standard whisky barrel size worldwide. Some distillers transfer their whisky into different barrels to "finish" or add qualities to the final product. These finishing barrels frequently aged a different spirit (such as rum) or wine. Other distillers, particularly those producing Scotch, often disassemble five used bourbon barrels and reassemble them into four casks with different barrel ends for aging Scotch, creating a type of cask referred to as