A blend of up to 40 carefully selected single malt and single grain whiskies left to mature in oak casks at the brand's home in Scotland for a minimum of four years. At that point, instead of bottling the blend, the mature liquid is married in handcrafted American oak casks, selected by master blender Stephanie Macleod. These barrels, bourbon and virgin ok, are heavily charred and then lightly scratched at the char layer to alter the flavor of the whisky. The liquid is then left to blend and breathe for additional months, a production process called finishing.