go to a two year college. get a degree in restraunt management. open a brew pub. a microbrewery seems a bit out of the question for a 21 yearold with one year of college
This is good advice, but I will stress, underline, scream, complain, and jump up & down to emphasize the idea that you will need to have some business instruction from your educational career.
There's 2 ways I can see you going about this. First, you want to own/run your own brewery. In that case, focus on business education. Knowing how to run a business will keep your business from tanking once you have a desirable product.
The second way is if you want to concentrate on brewing. At that point, keep homebrewing, but look into the educational options that focus on beer. This might mean traveling abroad where beer is looked at far more seriously than here in America. If you take this route, still have at least a brushing familiarity with business courses, but figure on finding someone who groks beer and is a good business man to actually "run" the business.
At this point, you'll either need people or money. The Small Business Association for your area is a good place to start. You can meet up with successful business owners or entrepreneurs who are willing to give you the venture capital you need to start your brewpub or microbrewery. To get this money though, you need a good, solid business plan, and you need a good contract lawyer on a retainer to make sure you don't get screwed in any way by your new partner. Once you find a good partner who will either invest in you or help you run your business, you can go to your lawyer and incorporate, get insurance, and do everything else you need to cover your ass and your assets. This is vital, especially since to brew you need a license from your state. Lots of red tape to jump through.
However, taken all of this into account, I'm going to say to keep your ass in college now. This is a piss poor economy, hops and barley prices are up, and I seriously wonder how much venture capital will be floating around to be had. In any event, figure out how you want to proceed first, and then apply yourself, push yourself through college towards that goal.
21 years old, 1 year of college, and no business experience/training will destroy your dreams before your very eyes. Line yourself up properly, make your move from a position of strength, not a gambling position.
Edit: I might actually incorporate before I go looking for investors actually. It's easier to just give them 500,000 shares of "poopy breweries inc" or whatever you call the business than have to contract a business deal from the ground up. Besides, incorporating is only a couple thousand maximum, and if you get someone to invest in you, but they don't simply want shares, it's not much to scrap your corp and start a new one. The SBA is good advice on this as well.
At the very, very least, you should know the difference between a partnership, sole proprietorship, LLC, S corps, and all the other different kinds of businesses you can run. It's a lot of paperwork and a lot of effort to do it, but it's important to not just hand it over to someone in the beginning because things can end up screwing you over down the road (as happened to me and my company last year).