Barrel.

Barrel. When used as a unit of measure, the quantity equal to 31 U.S. gallons. When used as a container, a consumer package or keg containing a quantity of beer listed in 25.156, or other size authorized by the appropriate TTB officer.

Source

27 CFR § 25.11

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Scoping language

When used in this part, where not otherwise distinctly expressed or manifestly incompatible with the intent thereof, terms have the meanings given in this section.

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