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.
Code of Federal Regulations
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:
1.12×53.73-47.75 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.