Most Irish whiskeys are distilled three times, although there are exceptions. Though traditionally distilled using the pot still method, in modern times a column still is used to produce the grain whiskey used in blends. By law, Irish whiskey must be produced in Ireland and aged in wooden casks for a period of no less than three years, although in practice it is usually three or four times that period. Unpeated malt is almost always used, the main exception being Connemara Peated Malt whiskey.
There are several types of whiskey common to Ireland: single malt, single grain, blended whiskey and uniquely to Ireland, pure pot still whiskey. The designation “pure pot still” as used in Ireland generally refers to whiskey made of 100% barley, mixed malted and unmalted, and distilled in a pot still made of copper. The “green” unmalted barley gives the traditional pure pot still whiskey a spicy, uniquely Irish quality. Like single malt, pure pot still is sold as such or blended with grain whiskey. Usually no real distinction is made between whether a blended whiskey was made from single malt or pure pot still.