Seattle-based Letterpress Distilling has collaborated with Copperworks to produce amaro cask-finished American Single Malt Whiskey. Copperworks American Single Malt Whiskey was matured in an American Oak barrel then rested in the amaro [a bittersweet grape brandy-based liqueur] cask for more than seven months before being bottled at 50% alcohol by volume [100 proof] . Copperworks […]