27 CFR 19.359: Remnants.

When at the end of a bottling run fewer bottles remain than the number necessary to fill a case, the remaining bottles may be placed in a case marked as a remnant case or kept uncased on the bonded premises until spirits of the same kind are again bottled. The remnant bottles may later be used to complete the filling of a case, or may be used for another lawful purpose such as replacing accidental breakage occurring on bonded premises.