27 CFR § 30.61 - Table 1, showing the true percent of proof spirit for any indication of the hydrometer at temperatures between zero and 100 degrees Fahrenheit.

---
identifier: "/us/cfr/t27/s30.61"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "27 CFR § 30.61 - Table 1, showing the true percent of proof spirit for any indication of the hydrometer at temperatures between zero and 100 degrees Fahrenheit."
title_number: 27
title_name: "Alcohol, Tobacco Products and Firearms"
section_number: "30.61"
section_name: "Table 1, showing the true percent of proof spirit for any indication of the hydrometer at temperatures between zero and 100 degrees Fahrenheit."
chapter_name: "ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY"
subchapter_number: "A"
subchapter_name: "ALCOHOL"
part_number: "30"
part_name: "GAUGING MANUAL"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "26 U.S.C. 7805."
regulatory_source: "T.D. ATF-198, 50 FR 8535, Mar. 1, 1985, unless otherwise noted."
cfr_part: "30"
---


# 30.61 Table 1, showing the true percent of proof spirit for any indication of the hydrometer at temperatures between zero and 100 degrees Fahrenheit.

This table shows the true percent of proof of distilled spirits for indications of the hydrometer likely to occur in practice at temperatures between zero and 100 degrees Fahrenheit and shall be used in determining the proof of spirits. The left-hand column contains the reading of the hydrometer and on the same horizontal line, in the body of the table, in the “Temperature” column corresponding to the reading of the thermometer is the corrected reading or “true percent of proof.” The table is computed for tenths of a percent.

|  |  |
| --- | --- |
| Temperature, °F | 75 |
| Hydrometer reading | 193 |
| True percent of proof | 189.5 |

Where fractional readings are ascertained, the proper interpolations will be made (see § 30.23). If the distilled spirits contain dissolved solids, temperature-correction of the hydrometer reading by the use of this table would result in apparent proof rather than true proof.

(Sec. 201, Pub. L. 85-859, 72 Stat. 1358, as amended (26 U.S.C. 5204))