Whiskey enthusiasts often wax romantic about the balance of this mash bill, or the elegant neck of that copper pot still and sometimes even about exotic yeasts, and how these things play out in the flavor of their favored spirits. Yet it’s not these things, but the cask and the time spent in it that is the single biggest player in what whiskey tastes like.
According to Chris Morris, Master Distiller at Woodford Reserve, aging in new white oak barrels gives his bourbon “100% of its color naturally, and approximately 50 to 60% of its aroma and flavor.” For decades, the choice of wood used in whiskey casks was standardized. In America, it was almost all new white oak, as mandated by Federal law. In Scotland and Ireland, most of the casks were old barrels imported from America, plus a few types from Europe.
With whiskey around the world surging in popularity, the wood choices are now expanding, as producers reach for new sources of oak and sometimes other woods, and this reach is turning out new flavors.