Food & Agr. Code, § 74658

(a) Any vintner who processes winegrapes into must, grape juice, or grape concentrate for the manufacture of nonalcoholic beverages other than nonalcoholic wine may apply to the commission for either an exemption from the assessment due pursuant to this chapter or for a refund of the assessment on that portion of his or her production used in the manufacture of nonalcoholic beverages other than nonalcoholic wine.

(b) In order to be eligible for the exemption or refund, the vintner shall file an affidavit with the commission attesting that the must, grape juice, or grape concentrate was, in fact, used for the manufacture of nonalcoholic beverages other than nonalcoholic wine. The commission shall render a determination on the claim. All approved claims shall be subject to verification through an independent audit of the claimant’s business records by the commission or its duly authorized agent.