Jack Daniels Single Barrel Cask Strength – Crafting something that endures for over 150 years takes time and character. You’ll find plenty of both in the people and history that make Jack Daniel’s. Selected by our Master Distiller and presented at 129 proof, this high character single barrel Tennessee Whiskey reflects the flavor imparted by our handmade, toasted and charred, American Oak barrels. Bottled a barrel at a time, Barrel Strength lifts Jack’s trademark vanilla and toasted oak flavors to bold new levels for an aromatic and smooth whiskey experience, complemented by notes of sweet brown sugar that give way to hints of dark spice.