Behind the Bottle: The Science of Proofing Down Spirits

Here's a dirty secret about the spirits industry: some distilleries treat proofing like an afterthought.

Take your barrel-strength whiskey. Cut it with water. Bottle it. Ship it. Done.

We don't work that way. And once you understand what proofing actually does to a spirit, you'll taste the difference. 

What "Proofing Down" Actually Means

When whiskey comes out of the barrel, it's not at bottling strength. Depending on how long it aged, where it sat in the rickhouse, and what the weather did that year, bourbon can come out anywhere from 110 to 140 proof. Sometimes higher.

Proofing down is the process of adding water to reduce that alcohol content to the final number you see on the label. Our Green Label sits at 90 proof. Our Blue Label at 102. Our Cask Strength releases? Those come straight from a single barrel: whatever proof nature gave us. The last one was 115 proof from a 9-year barrel.

Simple math, right? Add water until the numbers work.

Except it's not math. It's chemistry. And if you don't understand the chemistry, you're just diluting flavor instead of unlocking it.

The Water Problem

Here's where some distilleries fail before they even start.

Ethanol and water don't mix the way you think they do. When you combine them, they actually contract. The final volume is less than what you started with. The molecules bind together in clusters that change how flavor compounds interact with your palate.

Add the wrong water, and those clusters trap off-flavors. Add water too fast, and the spirit "breaks," turning cloudy as fatty acids and esters fall out of solution. Add water at the wrong temperature, and you get a harsh, disjointed product that never quite integrates.

The water itself matters more than most people realize. Municipal tap water carries chlorine, fluoride, and mineral profiles that vary by season. Well water brings iron and sulfur. Even "purified" water from a grocery store has been stripped so clean that it tastes flat and dead.

One of the many reasons we chose to locate our production facility in Bristol, Tennessee was its amazing water source: the South Holston River. Fed by Holston Lake (and known for its world renowned trout fishing) it is one of the most pristine mountain and spring fed water sources in the state of Tennessee, if not the whole country. The mountainous terrain plays a significant role due to its abundance of limestone, which acts as a naturally occurring filter. This natural filter removes iron while contributing calcium and magnesium (minerals that actually enhance mouthfeel and help carry flavor compounds).

But we don't stop there.

Molecular-Level Control

Our Bristol facility runs a reverse osmosis system that lets us adjust water chemistry at the molecular level depending on what we want to achieve in different parts of the process. We use Bristol’s mineral rich water during the mashing process. However, we directly inject live steam using RO water through the boiler to heat the cooker. Then, when distilling we use the same steam source to run our live steam injected stills.

This removes any possibility that chemical carry over will occur from the boiler. 

This isn't standard equipment. Most craft distilleries use basic filtration: in-line carbon filters, sediment filters, and maybe a UV light depending on the source. We're controlling mineral content down to parts per million because those numbers directly affect how the final spirit tastes. We have full control over the finished water profile. 

Too much calcium? The whiskey turns chalky. Too little? It tastes thin. The wrong pH? Flavor compounds that should hit your palate bright and clean come across muted or metallic. 

We can use the water that the great creator gave us and adjust, or completely build our own water profiles through reverse osmosis and mineral additions. 

Stephen spent five years in analytical research at Eastman Chemical before going legal with Tennessee Hills in 2014. He doesn't run this distillery like a farmhouse operation. He runs it like a chemical plant. That's why our Bristol facility can produce 100 barrels a week with consistency that most craft operations can't touch.

We use 100% Copper stills. Our 40-foot continuous column still and 500 gallon pot still  handles distillation. The R.O. system handles water. And that combination means every bottle that leaves here tastes exactly like it's supposed to.

Why Proof Points Aren't Arbitrary

Different spirits need different proof points. It's not marketing, it's flavor science.

Our Tennessee Mellowed Wheated Vodka is distilled to perfection and then sugar maple charcoal filtered just like a Tennessee whiskey. We bottle it at 80 proof because that's where the clean, soft wheat character shines without alcohol burn getting in the way, creating a truly unique Tennessee product. 

Our flavored whiskeys sit at 70 proof (higher than most competitors at around 60 proof) because the base spirit needs enough structure to carry notes of real whiskey without getting buried by over flavoring. Our Blood Orange whiskey at 60 proof would taste like orange candy. At 70, you taste the bourbon first, then the citrus lifts through.

Our straight bourbons and (and coming soon: our Tennessee whiskey) range from 90 to 115 proof depending on the expression. Green Label at 90 gives you vanilla, honey, and oak with approachable warmth. Blue Label at 102 pushes more complexity: the higher proof lets those rye spice notes cut through. Cask Strength at barrel proof delivers whatever that specific barrel developed over 7, 8, 9 years of aging.

Each proof point exists because that's where the spirit tastes best. Not because it's easier to produce. Not because it's cheaper. Because Stephen and our master distiller, Jason Franklin tasted batch after batch until they found the number.

Sounds like a pretty good time, huh?

The Marrying Process

Here's something most people don't know: proofed spirits need time.
When you add water to barrel-strength whiskey, the molecules don't instantly integrate.
The ethanol-water clusters need to reform. The flavor compounds need to be redistributed. The spirit needs to settle and mellow.

We let proofed batches marry before bottling. Not just because we're patient, but because we've tasted what happens when you skip this step. The spirit tastes disjointed and rough around the edges. Alcohol hot on the front, then sweet in the middle, then nothing on the finish. Proper marrying creates a unified experience from first sip to last.
Some commercial operations skip this entirely. Barrel to cut to bottle in 48 hours. Ship it.

We don't skip steps.

How to Taste the Difference

Next time you're comparing whiskeys, add a few drops of water to your glass and wait 30 seconds.

Quality proofing reveals itself. Slow proofing allows the chemistry to settle and the whiskey to harmonize, while rushed proofing risks breaking the very structure that carries flavor.

A well-proofed spirit opens up: new aromas emerge, flavors become more distinct, the finish extends. The water activates what's already there.

A poorly-proofed spirit falls apart. It gets thin. The flavors separate. That warmth you liked becomes harsh and disconnected.

This is why we obsess over water chemistry and proofing. Why we invested in reverse osmosis and give attention to the most minute details. Why Stephen and Jessica's chemistry background isn't just a story, it's the foundation of everything we make.

A good whiskey can become a great whiskey if handled properly after maturation. Instead of a simple math problem, we treat it like a chemistry solution.

Because that's what it is.

Visit Us

Want to see the process in person? Our tours in Bristol, walk you through distillation, barrel aging, and yes—proofing. You'll taste the difference water makes.

Book a tour here.

Stay #ResponsiblyRowdy.