The Lincoln County Process Gives Tennessee Whiskey Its Identity

If not for Lincoln County—a 571 square-mile rural area on the border of Alabama—Tennessee whiskey might be indistinguishable, at least by technical standards, from bourbon. Both whiskey types share the same basic rules: the mash needs to be at least 51% corn, distilled to a maximum of 80% ABV, aged in new charred American oak, have a barrel entry ABV maximum of 62.5%, and bottled at a minimum of 40%. Yet even with all those similarities, some tasters point to clear differences, with Tennessee whiskeys often considered softer and mellower in flavor. One reason is the Lincoln County Process, which is integral to Tennessee’s signature style. 

This method first materialized (at least by name—its actual history goes back thousands of years) in Tennessee during the mid-1800s and was then known as charcoal leaching, when Nathan “Nearest” Green taught Jack Daniel how to make whiskey in none other than Lincoln County (which has since been rezoned and no longer includes Jack Daniel). Over the years, the process hasn’t changed much except for the name: Unaged whiskey is sent through vats filled with charcoal made from sugar maple trees, with the end goal of removing impurities and smoothing (or “mellowing”) the flavors.

Charcoal filtering first materialized in Tennessee during the mid-1800s, when it was known as charcoal leaching. (Photo by Kristina Krug)

At Cascade Hollow, George Dickel whiskeys are filtered through mammoth, 14-foot vats full of charcoal that are first filled to the brim with new make then chilled—the chilling part being a Dickel exclusive—before the whiskey trickles through. “We lean very heavily into the charcoal mellowing, using it as a major contributor to the final character of the spirit,” says Nicole Austin. “Everything at the distillery was built around the idea that charcoal mellowing was going to play a major part. Sometimes in more modern production, people might default to a more traditional Kentucky-style of production, and their distillery might not integrate the charcoal mellowing process nearly as much.”

All Tennessee distillers must use the Lincoln County Process if they wish to call their products Tennessee whiskeys, with the lone exception of Prichard’s—which ironically is one of just two Tennessee distillers located in Lincoln County. The distillery gained exemption from the rule after owner Phil Prichard argued that charcoal filtering is not a technique his ancestor, Benjamin Prichard, ever used. Benjamin Prichard couldn’t have used charcoal filtering, as he was making whiskey decades before the process was even invented. 

Prichard’s was revived as a distillery by Phil Prichard in 1997; the first legal distillery in Tennessee in nearly 50 years. Its whiskey is made with white corn and Tennessee spring water, and is distilled through pot stills, as opposed to the column stills commonly used by many of its contemporaries. Nowadays, Prichard’s is more focused on rum, though Benjamin Prichard’s Tennessee whiskey remains integral to the range. 

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