Single malt Irish whiskey
Irish single malt whiskey must be distilled from a mash of malted barley without the addition of other grains or fermentable sugars. It must be matured in wooden (not necessarily oak) casks for at least three years. And as the term "single" implies, the whiskey must be from one distillery.
Single malt Irish whiskey is made in much the same way as the Scottish equivalent but with one key difference. While double distillation is the norm and triple distillation the exception in Scotland, in Ireland this is flipped with triple distillation being the norm. However, it's more nuanced that that.
Triple distillation of Irish single malt whiskey has been heavily marketed for decades by Bushmills, its most established producer, but even at Bushmills the recycling of faints and foreshots and the way the spirit moves through the process means that elements of the "triple distilled" spirit have passed though some six distillations.
The modern-day convention that Irish whiskey was triple distilled was busted by Cooley when the distillery was the trailblazer for the many independent distilleries that have since followed. Cooley recognised that historically Irish whiskey was also double distilled and so Cooley's malts follow the Scottish belief, that "they get it right the second time."