Whisky The Macallan 15 Year Old Triple Cask. The Macallan Triple Cask Matured 15 Years Old forms part of our Triple Cask Matured range a series of single malt whiskies crafted in a triple cask combination of European and American sherry seasoned oak casks and American ex-bourbon oak casks. An expert marriage of these three distinct cask types, this is a sublime single malt with vibrant orange and chocolate flavours.