California Code, Business and Professions Code - BPC § 23386

(a) Any manufacturer's, wine grower's, manufacturer's agent's, rectifier's, importer's, or wholesaler's license also authorizes the giving away of samples of the alcoholic beverages that are authorized to be sold by the license under the rules that may be prescribed by the department.  A retail license does not authorize the furnishing or giving away of any free samples of alcoholic beverages.

(b) Notwithstanding subdivision (a), an on-sale retail licensee authorized to sell wine may instruct consumers at the on-sale retail licensed premises regarding wines sold by the retail licensee.  Notwithstanding subdivision (a), an on-sale retail licensee authorized to sell distilled spirits may instruct consumers at the on-sale retail licensed premises regarding distilled spirits.  The instruction may include, without limitation, the history, nature, values, and characteristics of the product, and the methods of presenting and serving the product.  The instruction of consumers may include the furnishing of not more than three tastings to any individual in one day.  A single tasting of distilled spirits may not exceed one-fourth of one ounce and a single tasting of wine may not exceed one ounce.  Nothing in this subdivision shall limit the giving away of samples pursuant to subdivision (a).