Cal. Business and Professions Code § 25201

(a) A manufacturer, importer, or wholesaler of beer shall not use a container or carton as a package or container of a beer other than the beer as is manufactured by the manufacturer whose name or brand of beer appears upon the container or carton, or use as a package or container of a beer a container or carton which bears the name of a manufacturer of beer or the brand of any beer other than those of the manufacturer of the beer contained in the container or carton. (b) A beer manufacturer that refills any container supplied by a consumer shall affix a label that complies with this section on the container prior to its resale to the consumer. Any information concerning any beer previously packaged in the container, including, but not limited to, information regarding the manufacturer and bottler of the beer, or any associated brands or trademarks, shall be removed or completely obscured in a manner not readily removable by the consumer prior to the resale of the container to the consumer. This subdivision does not authorize a beer manufacturer to refill a container supplied by a consumer with a capacity of five liquid gallons or more.