What is the charcoal-filtering process used to make Tennessee whiskey before aging?

The charcoal-filtering process used to make Tennessee whiskey before aging is the Lincoln County Process.

In this method, newly made whiskey is slowly filtered through columns or vats filled with sugar maple charcoal before entering oak barrels. The charcoal treatment is intended to soften the spirit by removing some compounds and adding a distinctive smooth character.

The process is strongly associated with Tennessee whiskey, especially Jack Daniel’s. It is performed before maturation, not after the whiskey has spent years in a barrel. This timing distinguishes it from ordinary filtration or chill-filtration used by some producers after aging.

Tennessee whiskey also follows the basic federal requirements for bourbon, including a mash containing at least 51% corn and maturation in new charred oak containers. The Lincoln County Process is therefore a production identity rather than a separate grain category. The name refers to Lincoln County, Tennessee, where the method became historically associated with local whiskey making.