Malt whisky whisky regulations require malt whisky to be made in pot stills using water and malted barley without the addition of any other cereals, and the whisky must be aged for at least three years in oak casks. The use of new barrels is not required. Caramel coloring can be added, but no other additives are allowed. Irish whiskey regulations are almost identical to Scotch regulations. Malt whiskey must be distilled in a pot still from a mash of 100% malted barley, which may be peated or unpeated in character, although unpeated malt is typically used. All Irish whiskeys must be
Scotch whisky or "non-chill-filtered" has not been through a filtration process during bottling that removes compounds that some consumers see as desirable. Whisky is aged in various types of casks—and often in used sherry or port casks—during distinct portions of the maturation process, and will take on characteristics, flavour and aromas from such casks. Special casks are sometimes used at the end of the maturation process, and such whiskies may be labelled as "wood finished", "sherry/port finished", and so on. There are two basic types of Scotch whisky, from which all blends are made: Excluded from the definition of "single grain Scotch