Appleton Estate Rare Casks 12 Year Old is a minimum age rum as indicated by the number 12 displayed on the bottle. The rum is aged in Number One Select American Oak barrels. Appleton Estate Rare Casks 12 Year Old is a true expression of our Master Blenders craft and passion. The rare, golden rums that make up Rare Casks are hand-selected, and have all been aged for a minimum of 12 years.