Barrell Barrell Bourbon Cask Finish Series is a limited edition series launched in the fall and will introduce two blends each year. Up first, the Amburana is a blend of Indiana (5, 6, 7, & 10-year) and Kentucky (5-year) bourbon whiskeys, which were further matured in sustainable Amburana casks. The Barrell blending team created a bourbon blend of two mashbills with different char levels finished in Amburana casks. A vatting of individual casks without finishing was then layered in to add depth, richness, and complexity, ensuring the bourbon shines through first and foremost. Featuring a derived mash bill of corn (75%), rye (21%) and malted barley (4%), the blend was bottled at cask strength (116.42 proof).