27 CFR § 25.264 - Transfer between breweries.
(a) Authorized transfers. A brewer may remove from the brewery, without payment of tax, concentrate produced from beer for transfer to any other brewery of the same ownership (within the limits of ownership described in § 25.181).
(b) Record of concentrate transferred. When transferring concentrate between breweries, the shipping brewer shall prepare for each conveyance a serially numbered invoice or commercial record covering the transfer. The invoice will be clearly marked to indicate that concentrate produced from beer is being transferred. The invoice will contain the following information:
(1) Name and address of shipping brewer;
(2) Date of shipment;
(3) Name and address of receiving brewer;
(4) The number of containers transferred, the balling, percentage of alcohol by volume, and the total barrels of concentrate; and
(5) A description of the beer from which the concentrate was produced including the number of barrels, balling, and percentage of alcohol by volume.
(c) Disposition of invoice. On shipment of the concentrate, the shipping brewer shall send the original copy of the invoice to the receiving brewer and shall retain a copy for the brewery records. On receipt of the concentrate, the receiving brewer shall note on the invoice any discrepancies in the concentrate received and retain the invoice in the brewery records.