27 C.F.R. § 19.401 Inventories of wines and bulk spirits (except in packages) in processing account.
Title 27 - Alcohol, Tobacco Products and Firearms
Each proprietor shall take a physical inventory of wines and bulk spirits (except in packages) in the processing account at the close of each calendar quarter, and at such other time as the appropriate TTB officer may require. The results of the inventory shall be recorded in accordance with subpart W of this part. (Sec. 201, Pub. L. 85–859, 72 Stat. 1356, as amended (26 U.S.C. 5201))
Title 27: Alcohol, Tobacco and Firearms
PART 19—DISTILLED SPIRITS PLANTS
Subpart M—Processing Operations Other Than Denaturation and Manufacture of Articles
Inventories
§ 19.401 Inventories of wines and bulk spirits (except in packages) in processing account.

