Tennessee whiskey and the Lincoln County process
Tennessee whiskey follows most of the same rules as bourbon, then adds a step that happens before the spirit ever touches a barrel. That step is the Lincoln County process. Here is what it is, what the law requires and how to taste the difference.
Bourbon's close relative
Tennessee whiskey is an American whiskey made in the state of Tennessee. Its base recipe looks like bourbon: a mash of mostly corn with some rye or wheat and malted barley, distilled and then aged in new charred oak barrels. The result is sweet, rich and full of vanilla and caramel from the new wood.
The difference is one step between the still and the barrel. Most Tennessee whiskey is filtered through a deep bed of sugar maple charcoal before ageing. That step is called the Lincoln County process, or charcoal mellowing.
What the Lincoln County process is
Distillers burn stacks of sugar maple wood down to charcoal, break it into small pieces and pack it into tall vats, often deeper than a person is tall. The new make spirit drips slowly through the charcoal from top to bottom. Depending on the distillery, the spirit may take days to pass through.
Charcoal adsorbs some compounds from the spirit as it passes. Some of the harsher, heavier congeners and sulphur notes are reduced and a little character from the maple charcoal is added. The spirit that comes out is softer and slightly sweeter, with a faint sooty edge some tasters pick up.
The name comes from Lincoln County, Tennessee, where the method was used in the nineteenth century. County boundaries have moved since, so the name is history rather than geography.
What the law requires
Tennessee passed a state law in 2013 defining Tennessee whiskey. Under it, the whiskey must be:
- manufactured in Tennessee
- made from a grain mixture that is at least 51% corn
- distilled to no more than 80% ABV
- aged in new charred oak containers
- filtered through maple charcoal before ageing
- placed in the barrel at no more than 62.5% ABV
- bottled at a minimum of 40% ABV
Most of that list mirrors the rules for bourbon. The charcoal step and the Tennessee location are what make it Tennessee whiskey.
Is Tennessee whiskey bourbon?
This argument has run in bars for decades. Technically, most Tennessee whiskey meets the rules for bourbon and could carry the name. Producers choose not to, because Tennessee whiskey is a distinct identity with its own history and loyal drinkers.
A fair summary: Tennessee whiskey is a regional style made by bourbon methods with an extra filtering step. Call it a cousin rather than a twin. Our guide to single pot still Irish whiskey is a good comparison of how a single process choice defines a whole category.
Water and the limestone story
Tennessee distillers, like many in Kentucky, often talk about their limestone spring water. Water that has passed through limestone carries calcium and is low in iron, which is useful for fermentation and avoids dark colours or off notes in the spirit. Our guide to process water and reduction water explains why distillers care about iron and minerals.
Take marketing about water with some care. Good water helps, but the grain bill, yeast, still, charcoal and barrel do far more to shape the flavour in your glass.
What it tastes like
Tennessee whiskey usually tastes rounder and gentler than a bourbon of similar age and strength. Expect:
- sweet corn, caramel and vanilla
- banana or ripe fruit notes from the fermentation
- toasted oak and a little spice
- a soft, slightly sooty or smoky edge from the charcoal
The heat of a Tennessee summer pushes spirit hard into the barrel, so even young whiskey picks up plenty of oak colour and flavour. That is a useful lesson for Indian distillers maturing in a hot climate.
Taste it side by side
Pour 20 ml of a Tennessee whiskey and 20 ml of a bourbon at similar strength. Nose both. Taste each neat, then add a few drops of water. Notice whether the Tennessee whiskey feels smoother on the palate and whether you can pick up the charcoal. Keep water to hand, keep pours small and never drink and drive.
Your first step: find a Tennessee whiskey on a bar menu and order it neat with water on the side. Taste it slowly. Look for that soft edge the charcoal leaves.
Common questions
What is the Lincoln County process?
Filtering new make spirit through a deep bed of sugar maple charcoal before ageing. It softens the spirit and is the defining step for Tennessee whiskey.
Is Tennessee whiskey a bourbon?
Most Tennessee whiskey meets bourbon's rules, but producers label it Tennessee whiskey because of the charcoal step and its regional identity.
What are the rules for Tennessee whiskey?
Made in Tennessee from at least 51% corn, distilled to no more than 80% ABV, maple charcoal filtered, aged in new charred oak and bottled at 40% ABV or more.
