To proof alcohol, water is added until the liquid has reached a desired strength. When water is added to alcohol, heat is generated. At a distillery scale, hundreds of gallons of water are used at a time – enough to burn off many of the lighter, finer bourbon flavors. OLd Elk's choice to proof differently means that they can bottle every last drop of flavor, and retain the smoothness that is unique to Old Elk. While their Slow Cut™ proofing process takes significantly longer than most common recipes, taking the time to proof slowly makes all the difference.