Cellar aged for 6 years. 

CBS was born when we stumbled upon some bourbon barrels that had
previously housed maple syrup. We opted to put the same base beer as
KBS, an imperialized version of Breakfast Stout, in the maple barrels
and, after one taste, we knew we had something special. Rich maple
syrup, roasted coffee and velvety chocolate meld together in what can
only be described as a transcendental drinking experience.