US Standards of Identity for Whiskey
Bourbon must go into charred new oak barrels. Corn whiskey need not see a barrel at all. That contrast captures the precision of US whiskey law: grain matters, but so do distillation strength, the wood and what happens before bottling. The federal standards of identity define names from bourbon and rye to blended whiskey and American single malt whisky in 27 CFR 5.143. Separate provisions govern age statements and “bottled in bond”. [1][2][3]
This guide follows the official eCFR text current on 3 November 2026, checked in November 2026. It covers US federal definitions and their consequences for labels; the broader guide to whisky law explains how to approach rules across countries. [4]
In short
- US bourbon requires a mash containing at least 51% corn. [1]
- US straight bourbon requires at least two years in charred new oak barrels. [1]
- US whiskey aged less than four years generally requires an age statement, with an exception for bottled in bond. [3]
What the US standards of identity for whiskey require
Grain, oak and strength establish the basic federal class. Whiskey must be distilled from a fermented mash of any grain at below 95% ABV (190 US proof), retaining the taste, aroma and characteristics generally attributed to whiskey. It must be stored in oak barrels, except that corn whiskey need not be, and bottled at no less than 40% ABV (80 US proof). [1]
Individual types narrow those boundaries. Bourbon, rye and American single malt whisky have tighter distillation limits; barrel requirements and permitted additions also depend on the category. Meeting the broad whiskey definition is only the starting point. [1]
Either spelling, “whisky” or “whiskey”, is expressly permitted. Here, American whiskey follows the site's usual spelling, while “American single malt whisky” follows the wording of that federal category. [1]
Where the federal rules apply
Origin can determine the name, not just the address on the label. A place, state or region may appear in the designation only when distillation and any required ageing took place there. Blending and bottling may happen elsewhere. [1]
| Rule | Where it applies | Legal source | Checked |
|---|---|---|---|
| Bourbon must be distilled and aged in the United States | US bourbon designation | 27 CFR 5.143 [1] | November 2026 |
| American single malt requires US production and storage as specified below | US federal category | 27 CFR 5.143 [1] | November 2026 |
| Scotch, Irish and Canadian whisky must meet their home country's laws | US recognition as distinctive foreign products | 27 CFR 5.143, Table 2 [1] | November 2026 |
| Imported bottled in bond spirits need authorisation under the producing country's law | US bottled in bond labelling | 27 CFR 5.88 [2] | November 2026 |
Bourbon, rye and the named grain types
Bourbon begins with at least 51% corn in the fermented mash, and its origin is fixed: under US federal law, neither whiskey nor whiskey based distilled spirits may be called bourbon unless distilled and aged in the United States. Rye, wheat, malt and rye malt whiskey require at least 51% rye, wheat, malted barley and malted rye respectively. The regulation also provides for other named grain whiskey. [1]
These types share three firm production boundaries. Distillation must not exceed 80% ABV (160 US proof); storage must be in charred new oak barrels; and the spirit must enter those barrels at no more than 62.5% ABV (125 US proof). None permits neutral spirits. [1]
The rules on additions differ. Bourbon permits no colouring, flavouring or blending materials. Ordinary rye, wheat, malt, rye malt and other named grain types permit them under Table 1. The word “straight” brings further restrictions, explained below. [1]
Malt whiskey and American single malt whisky are separate federal standards. Malt whiskey requires at least 51% malted barley and charred new oak barrels. American single malt whisky requires a 100% malted barley mash, but allows several oak barrel types. The similar names describe distinct production rules. [1]
Corn whiskey, used barrels and light whiskey
For corn whiskey, the mash must contain at least 80% corn and distillation must not exceed 80% ABV (160 US proof). Storage is required only when an age is claimed. If stored, the spirit must enter used oak or uncharred new oak barrels at no more than 62.5% ABV (125 US proof). [1]
The barrel's history is therefore a decisive difference between corn whiskey and bourbon. A high proportion of corn alone does not make a spirit bourbon. [1]
“Whisky distilled from bourbon mash” belongs to another category, alongside the corresponding rye, wheat, malt, rye malt and other grain designations. These require at least 51% of the named grain, distillation at no more than 80% ABV (160 US proof), and storage in used oak barrels. The words “distilled from bourbon mash” describe something different from bourbon itself. [1]
Light whiskey takes its name from its production category, not a lower bottling strength. It is distilled above 80% ABV (160 US proof), but below the class limit of 95% ABV (190 US proof), and stored in used or uncharred new oak barrels. Light whiskey, blended light whiskey and whiskey distilled from bourbon or another named grain mash may be produced only in the United States. [1]
What “straight” adds
“Straight” adds time and restrictions to a whiskey type. It is an optional further designation: straight bourbon, rye, wheat, malt and rye malt whiskey must spend at least two years in charred new oak barrels. Distillation must be at no more than 80% ABV (160 US proof), with barrel entry at no more than 62.5% ABV (125 US proof). Neutral spirits, colouring, flavouring and blending materials are all prohibited. [1]
Straight corn whiskey keeps the corn category's different approach to wood. It requires at least 80% corn and at least two years in used or uncharred new oak barrels, entered at no more than 62.5% ABV (125 US proof). Straight American single malt whisky has its own barrel provisions, set out below. [1]
Blended whiskey is not one single formula
Read the full designation: US blended whiskey categories have different recipes. Their component percentages are measured on a proof gallon basis, not simply as a share of liquid volume. That basis matters when comparing labels or technical descriptions. [1]
| Federal category | Required whiskey component, on a proof gallon basis | Neutral spirits |
|---|---|---|
| Blended whiskey | At least 20% straight whiskey | Up to 80% [1] |
| Blended bourbon, rye or another named type | At least 51% of the named straight whiskey | Up to 49% [1] |
| Blended light whiskey | Light whiskey with less than 20% straight whiskey | Category component requirements apply [1] |
| Spirit whiskey | At least 5% whiskey or straight whiskey; straight whiskey below 20% | Up to 95% [1] |
A blend of straight whiskies, or blended straight whiskey of a named type, follows a different formula again. These are mixtures of straight whiskies aged at least two years, with no neutral spirits except as part of a flavour. “Blended” alone does not tell the whole story; the complete designation does. [1]
American single malt whisky
A 100% malted barley mash and distillation at the same US distillery define American single malt whisky. It must be produced in the United States, with distillation at no more than 80% ABV (160 US proof). Storage must also take place only in the United States, in oak barrels no larger than 700 litres. Used, charred new and uncharred new oak barrels are all permitted. [1]
Neutral spirits are prohibited, as are colouring, flavouring and blending materials, with one exception: caramel colouring is allowed if disclosed on the label. Straight American single malt whisky adds a minimum storage period of two years. [1]
The final rule took effect on 19 January 2025, with a transition for earlier standards. Spirits bottled before 19 January 2030 may carry labels designating American single malt whisky or straight American single malt whisky if they meet the standards in effect before 19 January 2025. A bottle carrying either name can therefore fall under those earlier standards during the transition. [1][5]
For the international distinctions, see single malt laws compared.
Bottled in bond is a separate designation
Bottled in bond means a shared kind, season, distiller and distillery, followed by at least four years in wood. Under 27 CFR 5.88, the spirits must be of the same kind, distilled in the same distilling season by the same distiller at the same distillery. They must spend at least four years in wooden containers and be bottled at 50% ABV (100 US proof). [2]
The spirits must remain unaltered except for filtration, chill proofing or similar physical treatment. Strength may be reduced only with pure water. The designation specifies wooden containers; it does not itself impose a universal requirement for charred new oak. [2]
Domestic bonded labels must identify the distillery and the plant numbers where the spirits were distilled and bottled. Imported spirits may use bottled in bond only when the producing country's law authorises it. The country must be named immediately after the statement. [2]
Age statements and distillation dates
For these federal provisions, age counts the time in oak barrels after distillation and before bottling. Bourbon, rye, wheat, malt, rye malt and straight whiskies generally require charred new oak for that ageing, with the specified exceptions for straight corn whiskey and straight American single malt whisky. [3]
Whiskey aged less than four years must carry an age statement, including blends containing such whiskey, unless labelled bottled in bond under 5.88. Where the whiskey contains no neutral spirits, the statement gives the age of the youngest whiskey. That age may be understated, but never overstated. [3]
For US whiskey stored in reused oak barrels, the required wording is “stored ____ years in reused cooperage”, rather than “years old”. Corn, light and American single malt whisky are exceptions. A distillation date may appear only alongside an age statement in the same field of vision. [3]
Where to go next
- Age Statement Rules Country by Country: compare age declarations across jurisdictions.
- Whisky Label Requirements by Country: place the category name within the wider label.
- Whisky Additives and Colouring Rules Around the World: compare permitted additions.
Sources
- Office of the Federal Register, eCFR. 27 CFR 5.143 Whisky, text current on 3 November 2026. https://www.ecfr.gov/api/versioner/v1/full/2026-11-03/title-27.xml?part=5§ion=5.143
- eCFR. 27 CFR 5.88 Bottled in bond, text current on 3 November 2026. https://www.ecfr.gov/api/versioner/v1/full/2026-11-03/title-27.xml?part=5§ion=5.88
- eCFR. 27 CFR 5.74 Statements of age, storage, and percentage, text current on 3 November 2026. https://www.ecfr.gov/api/versioner/v1/full/2026-11-03/title-27.xml?part=5§ion=5.74
- eCFR. Titles list, Title 27 currency metadata, November 2026: up to date as of 3 November 2026, last amended 26 October 2026. https://www.ecfr.gov/api/versioner/v1/titles.json
- Alcohol and Tobacco Tax and Trade Bureau, Federal Register. Addition of American Single Malt Whisky to the Standards of Identity for Distilled Spirits, T.D. TTB-199, 18 December 2024, 89 FR 102726; effective 19 January 2025. https://www.federalregister.gov/documents/2024/12/18/2024-29938/addition-of-american-single-malt-whisky-to-the-standards-of-identity-for-distilled-spirits
This desk research article was prepared from the site's verified LAW-US fact sheet and its recorded official regulatory sources.
Last checked: November 2026