I keep a bottle of Jack Daniel’s in my office, autographed by the late Master Distiller Jimmy Bedford. It’s one of my most prized possessions. On the label it says “Tennessee Whiskey,” and for years I read that as whiskey, made in Tennessee, and left it there. Then I started reading the rules behind the label.

The Tennessee part is the easy part. The harder question is whether Jack Daniel’s is whiskey, bourbon, or its own thing, and the answer sends you side-eyeing every label on the shelf.

Bourbon Has Rules. Strict Ones.

There probably wasn’t a single inventor of bourbon. Folks like Elijah Craig and Jacob Spears were distilling spirits as far back as the 1700s, long before the word meant what it does today. It evolved slowly, shaped by tradition, geography, and trial and error.

Bourbon has a strict legal definition. The mash has to be at least 51 percent corn. Push it above 80 percent and it becomes “corn whiskey.” The spirit has to be aged in new, charred American oak barrels, and it can’t enter the barrel above 125 proof. And one thing a lot of people get wrong: bourbon doesn’t have to come from Kentucky. It can be produced anywhere in the United States.

So when I started looking closely at how Jack Daniel’s is actually made, I was genuinely surprised. It follows every one of those rules.

So Why Doesn’t Jack Daniel’s Call Itself Bourbon?

That’s where the Lincoln County Process comes in.

After Jack Daniel’s is distilled by every rule that would qualify it as bourbon, it gets filtered through 10 feet of sugar maple charcoal before it ever touches a barrel. The spirit drips slowly through, which mellows it and strips away the harsher notes straight off the still.

That charcoal step earns it the name Tennessee Whiskey. The filtering changes the character of the spirit, giving Jack Daniel’s that smooth, slightly sweet finish people recognize. Gentleman Jack goes through it twice, before and after aging, which is why it tastes smoother than the Old No. 7.

More Than Jack and Dickel Now

For a long time the process belonged to two names. Jack Daniel’s and George Dickel made most of the Tennessee whiskey on the shelf, with Dickel chilling its whisky before a deeper bed of charcoal for a different finish.

But the list has grown. Nelson’s Green Brier, a Nashville distillery brought back by the founder’s descendants in 2014, runs a wheated mash bill through the process. Uncle Nearest, named for the formerly enslaved distiller who taught Jack Daniel the craft, launched in 2017 and became the fastest-growing whiskey in the country within a few years.

The newest name is AJ Bond, Sazerac’s first Tennessee whiskey, which landed this summer after about a decade in the making by distillers who came up at George Dickel. Collier and McKeel out of Nashville uses the process too. Every one of them runs the whiskey through sugar maple charcoal before the barrel.

Sometimes, There’s Confusion

Here’s where it gets a little tangled, and you might need a drink to follow along.

Not all whiskey made in Tennessee is Tennessee Whiskey, but all Tennessee Whiskey has to be made in Tennessee. A distillery can set up in Nashville, make a fine bourbon-style whiskey, and not call it Tennessee Whiskey if they skip the Lincoln County Process. The name carries a legal requirement.

And then there’s Prichard’s.

Benjamin Prichard’s Distillery is one of two distilleries actually located in modern-day Lincoln County, which is a little ironic, because it doesn’t use the Lincoln County Process at all. It’s the only Tennessee whiskey maker that doesn’t. They were grandfathered in before the state codified the charcoal filtering requirement in 2013. The exemption was written with dates that fit Prichard’s and nobody else, a clause carved to the shape of one company.

So the county that gives the process its name is home to the one distillery that doesn’t follow it.

Why Any of This Actually Matters

What’s inside the bottle came from deliberate choices. The people at Jack Daniel’s could put “bourbon” on every label and stay within their legal rights. They run the charcoal anyway, because that filtering is the thing they built their whiskey around.

The next time someone at a bar tells you Jack Daniel’s isn’t a real bourbon, you can pour yourself one and say, “You’re right. And here’s why.”