California Code, Business and Professions Code - BPC § 25622

(a) Beer to which caffeine has been directly added as a separate ingredient shall not be imported into this state, produced, manufactured, or distributed within this state, or sold by a licensed retailer within this state.

(b) The department may require licensees to submit product formulas as it determines to be necessary to implement and enforce this section. Any information required to be provided by any licensee to the department pursuant to this section shall be considered confidential and corporate proprietary information. This information shall not be subject to disclosure under the California Public Records Act (Division 10 (commencing with Section 7920.000) of Title 1 of the Government Code).