A highly sought-after rarity, Old Forester's 2017 Birthday Bourbon is composed of 120 12-year-old barrels from various parts of the Old Forester distillery warehouse. Composed of a mash bill of 72% corn, 18% rye, and 10% barley, this complex bourbon is believed to have a release yield of roughly 18,600 bottles, bottled at a barrel strength of 96 proof.