There is information on the AHA website, including text of applicable statutes. Florida reads:
Applicable Statutory Material
562.165 Production of beer or wine for personal or family use; exemption.–
(1) Notwithstanding any provisions to the contrary, a person who is not prohibited by s. 562.111 from possessing alcoholic beverages may produce beer for personal or family use, and not for sale, in the amounts provided in this section without payment of taxes or fees or without a license. The aggregate amount of such beer permitted to be produced with respect to any household shall be as follows:
(a) Not in excess of 200 gallons per calendar year if there are two or more such persons in such household.
(b) Not in excess of 100 gallons per calendar year if there is only one such person in such household.
(2) Notwithstanding any provisions to the contrary, a person who is not prohibited by s. 562.111 from possessing alcoholic beverages may produce wine for personal or family use, and not for sale, in the amounts provided in this section without payment of taxes or fees or without a license. The aggregate amount of such wine permitted to be produced with respect to any household shall be as follows:
(a) Not in excess of 200 gallons per calendar year if there are two or more such persons in such household.
(b) Not in excess of 100 gallons per calendar year if there is only one such person in such household.
(3) Any personal or family production of beer or wine in excess of the amount permitted in this section or any sale of such alcoholic beverages constitutes a violation of the Beverage Law.
(4) Wine and beer made under the provisions of this section may be removed from the premises where made for personal or family use, including use at organized affairs, exhibitions, or competitions, such as homemakers’ contests, tastings, or judgings. Wine or beer used under this subsection shall not be sold or offered for sale.
Note: The information presented here is to the best of our knowledge and should not be used as a substitute for legal advice specific to the laws of your state.
Note the disclaimer at the end! Also note section 4 which allows the use of homebrew at “organized affairs, exhibitions, or competitions…” but expressly limits “Wine or beer used under this subsection shall not be sold or offered for sale”. The bidding on a prize at an auction, sure sounds like offering for sale to me. However, the offering to allow them to brew up a batch by the successful bidder at your home might fall within the permissible guidelines, since it would ostensibly be made by the successful bidder with your oversight. Brewing a case for another that is sold at the auction seems to be a problem as I read it.
Now my disclaimer: I am not a licensed attorney in Florida and you should seek one out for advice before trying any of this! Perhaps you could also check with the Florida authority for guidance…