How to Read a Bourbon Label: Mash Bill, Age, Bottled-in-Bond and Proof
The legally enforced terms on a bourbon label are “bourbon,” “straight,” “bottled-in-bond,” the age statement, the proof, and the state of distillation. Almost everything else - “small batch,” “handcrafted,” “reserve,” “artisanal,” “founder's selection” - carries no legal definition and can be printed by anyone. Learning that split is the single highest-value skill in buying whiskey.
What legally makes a bourbon
To be sold as bourbon in the United States, a whiskey must meet all of the following:
- Made in the USA (not only Kentucky - that is the most common misconception)
- Mash bill of at least 51% corn
- Distilled to no more than 160 proof (80% ABV)
- Entered into the barrel at no more than 125 proof (62.5% ABV)
- Aged in new, charred oak containers
- Bottled at no less than 80 proof (40% ABV)
- No added coloring or flavoring
That last point is worth pausing on. Unlike tequila, where regulations permit small undisclosed additions, bourbon's rules prohibit added color and flavor outright. If a bourbon is dark, it got that way from wood. Our guide to additives in tequila covers the contrast in detail.
Note that there is no minimum aging period for plain “bourbon.” A whiskey that touched a new charred barrel for a day qualifies. The minimum arrives with the word straight.
Straight bourbon
“Straight” adds two requirements: at least two years in new charred oak, and no added coloring, flavoring or other spirits. Additionally, if a straight bourbon is under four years old, the label must state its age.
This produces a useful shortcut: a straight bourbon with no age statement is at least four years old. That is a floor, not a ceiling - it could be twelve - but it is a genuine piece of information hiding in an absence.
Bottled-in-Bond: the strictest label on the shelf
The Bottled-in-Bond Act dates to 1897, when it was essentially America's first consumer-protection food law. To carry it, a whiskey must be:
- The product of one distillation season, by one distiller, at one distillery
- Aged at least four years in a federally supervised bonded warehouse
- Bottled at exactly 100 proof (50% ABV)
- Labelled with the distillery of production
Bottled-in-bond is the highest ratio of guaranteed information to price anywhere in whiskey. You know the age floor, the exact proof, and - critically - who actually made it. Many bonded bottles sit at very ordinary prices.
Mash bill: the recipe
The mash bill is the grain mix. Corn must be at least 51%; the remainder is usually rye, malted barley, or wheat.
| Style | Typical mash bill | Character |
|---|---|---|
| Traditional / low rye | ~70–78% corn, 8–15% rye, malted barley | Balanced, caramel-forward, gently spiced |
| High rye | ~60–70% corn, 18–35% rye | Peppery, dry, mint and baking spice |
| Wheated | Corn plus wheat instead of rye | Softer, rounder, bread and honey notes |
| Four grain | Corn, rye, wheat and malted barley | Layered; varies widely by producer |
Mash bill disclosure is voluntary. Producers proud of their recipe usually publish it.
Age statements and proof
An age statement always refers to the youngest whiskey in the bottle. A twelve-year bourbon may contain older whiskey, but nothing younger.
Proof is simply ABV doubled: 90 proof is 45% ABV. Higher proof generally means more flavour intensity and a longer finish, and it means the producer diluted less. See our guide to single barrel, small batch and cask strength for how proof interacts with batching.
“Distilled in” vs “Produced by” vs “Bottled by”
This is where labels get evasive, and it's the most useful paragraph on this page.
- “Distilled by [X] in [State]” - X actually made it. The strongest claim available.
- “Produced by” - ambiguous. May involve blending or finishing rather than distilling.
- “Bottled by” - they put it in the bottle. Someone else distilled it.
Sourced whiskey is not inherently worse - some excellent brands source thoughtfully and are open about it. The problem is only when a brand implies a distilling heritage it does not have. Look for the state of distillation, which is required disclosure.
Terms with no legal meaning
Small batch. Handcrafted. Artisanal. Reserve. Select. Private stock. Founder's. Master's collection. Old. Heritage. None of these are defined or enforced. They may accompany excellent whiskey - they simply aren't evidence of it.
A 30-second label check
- Does it say straight? → at least two years, and four if no age is stated.
- Does it say bottled-in-bond? → four years, 100 proof, one distillery, named.
- Is there an age statement? → that's the youngest whiskey inside.
- What's the proof? → how much water was added.
- Who distilled it, and where? → the real provenance question.
- Ignore everything in cursive script.
Browse our whiskey collection, or explore Boone County Jail Distillery and Three Chord Whiskey.
Frequently asked questions
Does bourbon have to be made in Kentucky?
No. Bourbon can be made anywhere in the United States. Roughly 95% is made in Kentucky, which is where the assumption comes from.
What does bottled-in-bond mean?
A whiskey from one distillation season, one distiller and one distillery, aged at least four years in a federally supervised warehouse and bottled at exactly 100 proof, with the producing distillery named on the label.
What is a mash bill?
The recipe of grains used before fermentation. Bourbon requires at least 51% corn; the rest is typically rye, wheat or malted barley.
How old is bourbon with no age statement?
If it says “straight bourbon” with no age statement, it is at least four years old. Plain “bourbon” with no age statement has no guaranteed minimum.
Is wheated bourbon sweeter?
It tends to read as softer and rounder rather than sweeter in a technical sense, because wheat replaces rye's peppery bite. Many drinkers perceive that softness as sweetness.
Rare Tequilas sells to adults of legal drinking age only.