Rev. Rul. 54-510

Gins distilled at the same proof, by the same distiller and at the same distillery pursuant to the same formula, which are otherwise homogeneous, and which have been stored in metal drums or paraffin lined packages (in which latter case the gin does not come in contact with the wood surface) may be commingled for convenience in taxpayment or bottling under the authority of section 190.413 of Regulations 15 and section 185.621 of Regulations 10. Such gin so commingled is not subject to the rectification tax. Homogeneous gins may be commingled regardless of the period of storage thereof in the metal drums or paraffin lined packages. However, where there is any doubt as to the homogeneity of the gins to be commingled, a determination thereof should be made by the laboratory of the office of the Assistant Regional Commissioner, Alcohol and Tobacco Tax, for the region in which the warehouse or rectifying plant is located, in the manner prescribed by section 190.698 of Regulations 15.