Beer imported or brought into the United States in bulk containers may, under such regulations as the Secretary may prescribe, be withdrawn from customs custody and transferred in such bulk containers to the premises of a brewery without payment of the internal revenue tax imposed on such beer. The proprietor of a brewery to which such beer is transferred shall become liable for the tax on the beer withdrawn from customs custody under this section upon release of the beer from customs custody, and the importer, or the person bringing such beer into the United States, shall thereupon be relieved of the liability for such tax.