§30.32. Determination of proof obscuration. — Inbound Citations

A proprietor may determine, as provided in § 30.32 of this chapter, the proof obscuration of spirits to be bottled on the basis of a representative sample taken from a storage tank before the transfer of the spirits to the processing account or from a tank after the spirits have been dumped for processing, whether or not combined with other alcoholic ingredients. The obscuration will be determined after the sample has been reduced to within one degree of bottling proof. Only water may be added to a lot of spirits to be bottled for which the determination of proof obscuration is made from a sample under this section. The proof obscuration for spirits gauged under this section must be frequently verified by testing samples taken from bottling tanks before bottling.

(b) Except as otherwise authorized by the appropriate TTB officer, the proof of spirits containing not more than 600 milligrams of solids per 100 milliliters of spirits shall be determined by the use of a hydrometer and thermometer in accordance with the provisions of § 30.23 except that if such spirits contain solids in excess of 400 milligrams but not in excess of 600 milligrams per 100 milliliters at gauge proof, there shall be added to the proof so determined the obscuration determined as prescribed in § 30.32.

The proof of spirits shall be determined to the nearest tenth degree which shall be the proof used in determining the proof gallons and all fractional parts thereof to the nearest tenth proof gallon. The proof of spirits containing solids of 400 milligrams or less per 100 milliliters shall be determined by the use of a hydrometer and a thermometer in accordance with the provisions of § 30.23. However, notwithstanding the provisions of § 30.31, the proprietor may, at their option, add to the proof so determined the obscuration determined as prescribed in § 30.32.