Has char levels in the barrels increased along with barrel proof?

[Gillman]

Todd, another solution was/is adding older whiskey (than what was generally dumped), certainly where 80 proof was being bottled. I recall someone from Jack Daniels stating, when the drop occurred in the U.S., that if the color was too light they could adjust it by adding a little older stock. Of course that could increase the cost noticeably if too much was needed for the purpose, which makes me wonder again if they took a closer look at the barrel at this time. Interesting that the char numbers are a relative thing, and this may explain too the different maturation results you get even from barrels next to each other.

Gary