You have it completely backwards. The charcoal barrels cost as much as $600 to make. They mellow the whiskey and give it color. They also add to the distinct sour mash flavor in which you can taste hints of caramel, oak, vanilla, etc.
Dickel is an amazing Tennessee Whisky. I is not mass marketed but oh my goodness what flavor.
Kentucky bourbons use a quite inferior process and it tastes like it.
You are confused, my friend. New, charred oak barrels are required by federal law for all bourbon whiskey made in this country. Federal Law:
The Federal Standards of Identity for Distilled Spirits (27 C.F.R. 5) state that bourbon made for U.S. consumption must be:
Produced in the United States
made from a grain mixture that is at least 51% corn
aged in new, charred oak barrels
distilled to no more than 160 (U.S.) proof (80% alcohol by volume)
entered into the barrel for aging at no more than 125 proof (62.5% alcohol by volume)and be
bottled (like other whiskeys) at 80 proof or more (40% alcohol by volume).
Almost all whiskey made in Tennessee qualifies by law a straight bourbon. Tennessee law currently requires the use of the Lincoln County process (filtering through charcoal) in order to be labeled Tennessee whiskey. Pritchard’s has an exemption from this law.
As a general statement, Tennessee whiskey is bourbon, but not all bourbon can be called Tennessee whiskey. If you like it, drink it and enjoy.