I dont know if you can plan a tour ahead, you definitely can't through Disney. Your best bet is to call the Brewery ahead and ask if they can schedule a tour or if they can tell you the next time the brewmaster will be there.
We got lucky and arrived while the brewmaster was there, after we checked in we asked for a tour and the hostess arranged it to be done. The brewmaster is great, courteous and knows his stuff! We had a great time and learned some very interesting facts about brewering. It was enlightening to learn how the beer we ended up drinking afterwards was made.