[Code of Federal Regulations]
[Title 27, Volume 1]
[Revised as of April 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 27CFR30.66]

[Page 818]
 
            TITLE 27--ALCOHOL, TOBACCO PRODUCTS AND FIREARMS
 
 CHAPTER I--ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE 
                                TREASURY
 
PART 30_GAUGING MANUAL--Table of Contents
 
                       Subpart E_Prescribed Tables
 
Sec. 30.66  Table 6, showing respective volumes of alcohol and water and 
the specific gravity in both air and vacuum of spirituous liquor.

    This table provides an alternate method for use in ascertaining the 
quantity of water needed to reduce the strength of distilled spirits by 
a definite amount. To do this, divide the alcohol in the given strength 
by the alcohol in the required strength, multiply the quotient by the 
water in the required strength, and subtract the water in the given 
strength from the product. The remainder is the number of gallons of 
water to be added to 100 gallons of spirits of the given strength to 
produce a spirit of a required strength.

    Example. It is desired to reduce spirits of 191 proof to 188 proof. 
We find that 191 proof spirits contains 95.5 parts alcohol and 5.59 
parts water, and 188 proof spirits contains 94.0 parts alcohol and 7.36 
parts water.

95.5 (the strength of 100 wine gallons of spirits at 191 proof) divided 
by 94.0 (the strength of 100 wine gallons of spirits at 188 proof) 
equals 1.01.
7.36 (the water in 188 proof) multiplied by 1.01 equals 7.43.
7.43 less 5.59 (the water in 191 proof spirits) equal 1.84 gallons of 
water to be added to each 100 wine gallons of 191 proof spirits to be 
reduced.


This rule is applicable for reducing to any proof; but when it is 
desired to reduce to 100 proof, it is sufficient to point off two 
decimals in the given proof, multiply by 53.73, and deduct the water in 
the given strength. Thus, to reduce 112 proof spirits to 100 proof:

1.12x53.73-47.75 equals 12.42 gallons of water to be added to each 100 
wine gallons of spirits to be reduced.


This table may also be used to obtain the proof gallonage of spirituous 
liquor according to weight and percent of proof.

    Example. It is desired to determine the number of gallons in 400 
pounds of spirits of 141 percent of proof. Multiply the weight of one 
gallon of water in air by the specific gravity in air of the spirits--
8.32823 by 0.88862--the product (7.40063) divided into 400 gives 54.049 
wine gallons, which rounded to the nearest hundredth is 54.05 and 
multiplied by 1.41 gives 76.2 proof gallons. In rounding off where the 
decimal is less than five, it will be dropped; if it is five or over a 
unit will be added.

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