Cal. Rev. & Tax. Code § 32178

Any wine grower may claim and shall be allowed credit in any tax report filed or assessment made under this part with respect to the tax paid by him on wine sold to a wine rectifier and which has been exported from this State by the wine rectifier or sold for export by the wine rectifier and thereafter actually exported from this State. The board shall make rules prescribing the procedure for claiming and allowance of the credit.