To sip Barrel Proof is to experience Bourbon in its purest form: uncut, straight from the barrel, and without chill filtering. Each batch of Barrel Proof contains an uncut selection of 12-year-old Bourbon bottled straight from the barrel. As a result, each batch varies by proof.The batch number on the label provides specific information about each batch. The first letter indicates the order of the release for that year, starting with "A." The first number represents the month of the release. The third and fourth digits indicate the year.