The Whistler Irish Whiskey The Blue Note Single Malt is a 750 ml bottle of Irish whiskey. It is a single malt whiskey, meaning it is made from 100% malted barley. The whiskey is aged in ex-bourbon barrels for a minimum of three years, giving it a smooth and mellow flavor. The whiskey has notes of honey, vanilla, and toasted oak, with a hint of spice. It is a great choice for sipping neat or on the rocks.