ATF Ruling 912 The Bureau of Alcohol, Tobacco and Firearms (ATF) has been asked whether AntonPaar density meter DMA58 may, in addition to MettlerPaar density meters DMA55, DMA46, and DPR2000, be used in lieu of a hydrometer and thermometer to determine the proof of distilled spirits. By way of background, ATF Rul. 823, A.T.F.B. 821 15, authorized the use of the DMA55 for determining the proof of high solid distilled spirits products which contained solids in excess of 600 milligrams per 100 milliliters at gauge proof. ATF Ruling 823 was superseded by ATF Rul. 8512, A.T.F.B. 19853 44, which held that the DMA55 could be used for all proof determinations, including tax determinations. ATF Ruling 8512 also held that the DMA46 could be used to determine the proof of all distilled spirits, but that the instrument was too unreliable to be used for tax determination purposes. ATF Ruling 8512 was amplified by ATF Rul. 862, A.T.F.B. 19861 95, which authorized the use of the DPR2000 in determining the proof of all distilled spirits for tax determination purposes. 27 C.F.R. 30.31 prescribes a number of procedures to be used in determining the proof of spirits. These procedures vary depending on the extent to which the proof is obscured due to the presence of interferences such as dissolved solids. All of the procedures described in section 30.31 utilize a hydrometer and thermometer, unless the Director authorizes or recognizes a different approved method to determine the proof of distilled spirits. AntonPaar submitted technical information regarding the specifications and performance data of the DMA58. This information, which was evaluated by the ATF laboratory, demonstrates that the DMA58 provides accuracy comparable to the hydrometer and thermometer method. As a result of these studies, ATF has concluded that the DMA58 is reliable to the extent that it can be used in lieu of the hydrometer and thermometer to determine the proof of all distilled spirits for tax determination purposes. Held, AntonPaar density meter DMA58, in addition to MettlerPaar density meters DMA55, DMA46, and DPR2000, is recognized as an approved method under 27 C.F.R. section 30.31 to determine the proof of distilled spirits whenever a proof determination is required, with the exception that the DMA46 density meter may not be used to determine the proof of spirits for tax determination purposes. Provided, these density meters are not approved for use in determining the proof of denatured spirits solutions in those instances where a hydrometer and thermometer do not provide an acceptable method of proof determination under the regulations. Provided further, use of the density meters does not eliminate the need to add obscuration to the apparent proof determined by such meters when spirits contain more than 400 milligrams, but not in excess of 600 milligrams of solids per 100 milliliters at gauge proof (27 C.F.R. section 30.31(b)). Provided furthermore, that to make a true proof determination of spirits with such a high solids content, the spirits are first distilled in a small laboratory still and restored to the original volume and temperature by the addition of pure water to the distillate (27 C.F.R. section 30.31(c)). ATF Rulings 8512, A.T.F.B. 19853 44 and 862, A.T.F.B. 19861 95 are superseded. 27 CFR 30.31: (Also 30.32, 19.91, 19.383, 19.454, 19,517, and 19.537)
