Barrell Bourbon 15 Year Cask Strength - " A fifteen year-old blended Bourbon assembled by a master. " It is a collection of Bourbons from Kentucky, Tennessee, and Indiana — all aged a minimum of fifteen years — collected and expertly married in Kentucky. The mash bill consisted of corn, rye, and malted barley aged to perfection and bottled at a powerful 52.6% ABV so you can savor every drop. And savor you will… this wonderful dram is layered and complex.