Bourbon vs Tennessee Whiskey: Key Differences
The question of whether Tennessee whiskey is bourbon — or bourbon is Tennessee whiskey — is one of the more reliably contentious debates in American spirits. It is a dispute that combines genuine technical differences, fierce state pride, regulatory history, and a great deal of marketing interest from producers on both sides of the state line. Understanding what actually separates these two categories of American whiskey requires looking carefully at what the regulations say, what the Lincoln County Process actually does chemically, and why the distinction matters to the people who make and drink these spirits.
The short answer, which both sides tend to accept as their starting point, is this: technically, under federal law, Tennessee whiskey is bourbon. It meets all the federal Standards of Identity requirements for bourbon — grain mash of at least 51 percent corn, distilled below 160 proof, entered into new charred oak barrels below 125 proof, and without additives beyond water and caramel colour. Tennessee whiskey producers, particularly Jack Daniel's, have historically rejected the bourbon label despite meeting its requirements, choosing to differentiate their product on the basis of the Lincoln County Process and Tennessee state law.
What the Lincoln County Process Actually Is
The Lincoln County Process is the defining technical differentiator between Tennessee whiskey and bourbon. New-make spirit — the white dog that comes off the still — is filtered through a thick layer of sugar maple charcoal before it is placed in the barrel for ageing. The charcoal filtration typically involves the spirit dripping slowly through ten feet or more of packed maple charcoal, a process that takes several days per batch. The charcoal is produced on-site at major Tennessee distilleries by burning sugar maple wood in large stacks.
The chemistry of charcoal filtration is reasonably well understood. The activated carbon in the maple charcoal adsorbs certain congeners — particularly sulfur compounds and some heavy fatty acids — that contribute to harsher flavour characteristics in unfiltered new-make spirit. The process is essentially a large-scale version of the activated carbon filtration used in water purification, adapted to the specific congener profile of corn-forward American whiskey.
Jack Daniel's in Lynchburg, Lincoln County, has been using this process continuously since its founding in the 1860s. The distillery uses charcoal it burns in open-air ricks on the distillery grounds — a distinctive process that can be observed by visitors. George Dickel in Tullahoma, the other major Tennessee whiskey producer, also uses maple charcoal filtration but applies it to slightly chilled spirit, a difference from Jack Daniel's that Dickel credits with influencing its flavour profile.
Tennessee Law Codifies the Distinction
In 2013, Tennessee passed a state law formally defining Tennessee whiskey and requiring the Lincoln County Process as a condition of using that designation. The law specifies that Tennessee whiskey must be produced in Tennessee from a grain mash of at least 51 percent corn, filtered through maple charcoal before ageing, and aged in new, charred white oak barrels. The legislation was specifically designed to protect the Jack Daniel's and George Dickel styles against producers who might want to use the "Tennessee whiskey" name without following their production traditions.
The law was not without controversy. Benjamin Prichard's, a small Tennessee distillery that had been making whiskey without charcoal filtration, was grandfathered in as an exception because it had been producing its style before the law was enacted. More broadly, some craft producers argued that mandating the Lincoln County Process was an anticompetitive measure that protected established producers at the expense of smaller operators trying different production methods. The debate about the Tennessee law mirrors similar arguments about geographical indications in wine and spirits globally — where the line sits between protecting legitimate tradition and preventing legitimate innovation.
Flavour Differences in the Glass
Whether the Lincoln County Process produces a perceptible flavour difference is genuinely contested. Proponents — and Jack Daniel's marketing department — argue that the charcoal mellows the spirit, producing the characteristic "smoothness" that the brand has emphasised in its messaging for decades. The charcoal filtration removes certain congeners that contribute harsh or sulphurous notes, and the resulting spirit enters the barrel with a slightly different congener profile than unfiltered bourbon.
Critics of the distinction argue that the flavour contribution of charcoal filtration is minimal compared to the much larger flavour variables of grain bill, yeast, distillation proof, barrel char level, and warehouse conditions. A bourbon entered into a number four char barrel in a top floor of a Kentucky rickhouse will undergo more dramatic flavour change in two years than any charcoal filtration is likely to produce. Jack Daniel's and George Dickel are both relatively soft, approachable whiskeys by the standards of American whiskey broadly — but that character is at least partly attributable to their grain bills, yeast strains, and ageing practices, not only to the Lincoln County Process.
The Jack Daniel's Question
Jack Daniel's is by far the most consumed American whiskey in the world by volume. Produced at the distillery in Lynchburg, Moore County (yes, Moore County, not Lincoln County — the distillery moved county lines at some point in its history while retaining the name), it is distributed in more than 170 countries and represents a substantial fraction of global American whiskey consumption.
The core product — Old No. 7, the black label — is made from a mash bill of 80 percent corn, 8 percent rye, and 12 percent malted barley, distilled in large copper column stills with a doubler, charcoal filtered, and aged in new charred American white oak barrels in the distinctive multi-storey metal warehouses of the Lynchburg campus. At bottling, it is diluted to 40 percent ABV (80 proof) for most markets, although higher-proof expressions including Gentleman Jack (double charcoal filtered) and the Single Barrel series are available.
The Single Barrel series in particular has drawn serious attention from whiskey enthusiasts — individual barrels selected at between 94 and 100 proof, bottled unfiltered from a single warehouse location, with significant variation between barrels reflecting different warehouse positions and ageing environments. These expressions demonstrate that within the Jack Daniel's system, genuine complexity is achievable, and they make the Lincoln County Process argument easier to engage with at a flavour level.
George Dickel: The Other Tennessee Whiskey
George Dickel is significantly smaller in production than Jack Daniel's and substantially less well-known internationally, but it has a devoted following among American whiskey enthusiasts. Produced at the Cascade Hollow Distillery in Tullahoma, the brand uses a slightly different mash bill and, crucially, chills the spirit before charcoal filtration — a step that Dickel claims removes additional congeners not captured by room-temperature filtration.
The Dickel character is notably softer and creamier than Jack Daniel's, and the distillery has recently been celebrated for releasing cask-strength and aged expressions that have won significant critical attention. The Dickel Aged 17 Years expressions have demonstrated that Tennessee whiskey, given sufficient time in wood, develops a complexity and depth that challenges any dismissal of the category as a novelty or merely a marketing distinction.
What the Debate Reveals
The bourbon versus Tennessee whiskey argument ultimately reveals something important about how American whiskey identity has been constructed. Bourbon is a federal category; Tennessee whiskey is both a federal category (defined in the federal standards since 1941) and a state-protected designation. The producers who make Tennessee whiskey have generally preferred to own a distinctive identity rather than shelter under the more famous bourbon umbrella, even though they qualify for it.
The best way to resolve the question for yourself is to taste them side by side. Select a Kentucky bourbon and a Tennessee whiskey from similar grain bills and at similar ages, and assess what the Lincoln County Process contributes — or doesn't — in the glass. Then use the distillery map to plan visits to the Tennessee and Kentucky distilleries that are making the strongest cases for their respective production traditions.