Bushmills Irish Whiskey Adds Caribbean Rum Cask Finish To Its Lineup Bushmills Irish Whiskey Adds Caribbean Rum Cask Finish To Its Lineup One of the world’s oldest licensed whiskies, Bushmills, has got something new … a Caribbean rum cask finish. The first in a series of new cask finish products from Bushmills Irish Whiskey that will be known as the Bushmills Original Cask Finish range, the Caribbean Rum Cask Finish was unveiled last week across the island of Ireland, and then on to whiskey markets across the world. Bushmills’ describes the Cask Finish as their “award-winning single malt used in Bushmills Original Irish Whiskey, finished in hand-selected fine oak Caribbean Rum casks.” It’s then blended with the brand’s triple-distilled Irish grain whiskey to create tropical fruit and dry spice flavors.