27 CFR § 25.276 - Operations and records.
(c) Records. The operator of a pilot brewing plant must maintain records which, in the opinion of the appropriate TTB officer, are appropriate to the type of operation being conducted. These records will include information sufficient to account for the receipt, production, and disposition of all beer received or produced on the premises, and the receipt (and disposition, if removed) of all brewing materials. These records will be available for inspection by an appropriate TTB officer.