Rev. Rul. 59-106

Section 170.190 of the Miscellaneous Regulations Relating to Liquor provides, in part, that, when spirits in packages are to be dumped for mingling, the proof of the spirits in the tank shall be adjusted to a whole degree of proof and such adjusted proof shall be regarded as the proof of the spirits run into all packages filled from the tank. Held , when distilled spirits are mingled under the provisions of sections 170.185 through 170.196 of the regulations and the proof is reduced in the tank in accordance with section 170.190 of the regulations, the spirits may be reduced to any whole degree of proof which is not less than that to which the spirits could have been reduced on entry. However, in no instance shall the reduction be such that the volume in the tank after reduction will exceed the total capacity of the packages from which the spirits were dumped. Caution should be exercised regarding the requirement for tax payment of below proof spirits on a wine gallon basis.