One of the innovations at Compass Box was the notion that French oak had more applications than just aging French wine. Whereas the method used to incorporate that French oak into their barrels ran into trouble with The Spice Tree during its initial release, The Oak Cross has been nothing but smooth sailing. After primary maturation in a variety of American oak casks, the whiskey is married and put back into ex-bourbon casks with new French oak heads for a further 24 months of aging. The use of new French oak heads on the barrels is unique to Compass Box, while the two years of finishing used in the Oak Cross is unusually long by scotch-making standards, as a mere several months of finishing is more common.