Irish whiskey must include malted barley and may include other un malted cereal grains, resulting in four main types of whiskey.
Malt Irish whiskey is made using 100% malted barley and distilled in pot stills. Single malt whiskey comes from only one distillery.
Pot Still Irish whiskey is made from a mash of a minimum 30% malted and a minimum 30% un malted barley, with up to 5% of other cereals added, and is distilled in pot stills. Single pot still whiskey comes from only one distillery.
Grain Irish whiskey is made using no more than 30% malted barley in combination with other whole un malted cereals—usually corn, wheat, or barley—and is distilled in column stills. Single grain whiskey comes from only one distillery.
Blended Irish whiskey is a mixture of any two or more of the styles of malt, pot still, and grain whiskey.