Every batch of Gladstone Axe American Oak is made from 100% malted barley and aged in American oak barrels that were previously used for bourbon production. Aging the scotch whisky in ex-bourbon barrels imparts mellow sweet notes to the blend of malt whiskies that compose this one-of-a-kind scotch. Gladstone Axe American Oak is made from a selection of malt whiskies from 14 different Highland and Islay malt distilleries.