U.S. regulations state that an individual can brew up to 100 gals/yr
     for personal consumption or up to 200 gals/yr per family without
     being subject to taxes. Other countries will certainly have different
     regulations. State laws often override the Federal tax law with more
     stringent regulations or ban any homebrewing, so check locally. In
     any case, you cannot sell your homebrew. Also, be aware that the
     presence of homebrew supply stores does not imply that homebrewing is
     legal in your state. More often, in a strange quirk of law-making, it
     is legal to sell the supplies, but illegal to make beer with them!?