27 CFR §25.261

1. (a)Authorized processes. A brewer may, in accordance with this subpart—
   1. (1)Produce concentrate from beer,
   2. (2)Reconstitute beer from concentrate,
   3. (3)Transfer concentrate from one brewery to another brewery of the same ownership, and
   4. (4)Remove concentrate without payment of tax for exportation, or for transfer to and deposit in a foreign-trade zone for exportation or for storage pending exportation in accordance with part 28 of this chapter.
2. (b)Brewery treatment of concentrate. Beer reconstituted from concentrate in accordance with this subpart shall (except with respect to the additional labeling of reconstituted beer under § 25.263) be treated the same as beer which has not been concentrated and reconstituted.