27 CFR § 19.326 - Mingling or blending of spirits for further storage.
A proprietor may mingle or blend spirits in the storage account according to the following rules:
(a) Spirits distilled at 190° or more of proof, whether or not later reduced, may be mingled in storage.
(b) Domestic spirits distilled at less than 190° of proof may be mingled for withdrawal or further storage if the spirits:
(1) Are of the same kind; and
(2) Were produced in the same State.
(c) Imported spirits distilled at less than 190° of proof may be mingled for withdrawal or further storage if the spirits:
(1) Are of the same kind;
(2) Were produced in the same foreign country; and
(3) Were treated, blended, or compounded in the same foreign country and the U.S. import duty was paid at the same rate.
(d) Imported spirits distilled at less than 190° of proof that are recognized as distinctive products under part 5 of this chapter may be mingled for withdrawal or further storage if the spirits:
(1) Are of the same kind;
(2) Were produced by the same proprietor in the same foreign country; and
(3) Were treated, blended, or compounded by the same proprietor in the same foreign country and the U.S. import duty was paid at the same rate.
(e) Fruit brandies distilled from the same kind of fruit at not more than 170° of proof may, for the sole purpose of perfecting such brandies according to commercial standards, be blended with each other, or with any blend of such fruit brandies in storage. Rums may, for the sole purpose of perfecting them according to commercial standards, be blended with each other, or with any blend of rums.
(f) Packaging after mingling or blending must be done under the provisions of § 19.324. The mingled or blended spirits may be returned to the packages from which they were dumped, or as many of the packages as needed.