Irish whiskey comes from Ireland (where whiskey was first invented in the 15th century) and can be made from malted and unmalted barley. It has a reputation for being a lighter, gentler spirit, because Irish distillers often triple distill their whiskey to remove as many impurities (‘congeners’ is the technical term) as possible before barreling. Like scotch, some varieties of Irish whiskey can be made with peated malts but it is much less common.

Once distilled, the spirit must also spend a minimum of three years in wooden barrels before it can be called whiskey. Higher quality (and more expensive) whiskeys often spend a lot longer maturing in the barrels.