Bourbon cask wood (3)

I believe the answer is:
oak
(Other definitions for oak that I've seen before include "Strong hardwood" , "The King of the Forest" , "Acorn tree" , "Traditional British tree" , "Common deciduous tree" .)
I believe the answer is:
oak
(Other definitions for oak that I've seen before include "Strong hardwood" , "The King of the Forest" , "Acorn tree" , "Traditional British tree" , "Common deciduous tree" .)