I've wondered about this. Isn't your production volume limited by your fermentation/brighting capacity? Especially if you plan to not filter or pasteurize. And would states require pasteurization because if so, then there goes the specialness of most homebrews.
I mean in my house right now I could brew 30 gallons in one day and get them into a fermenter. But then I would not be able to brew for a few weeks if I wanted to age my beer properly.
So my question is, how do breweries get around this limitation? Do they have 21 sets of fermentation tanks?
No, they brew on a larger scale. We've lately been fermenting in my conical and sanke kegs. Generally about 12-20 gallon batches.
Shorten your time of fermentation with a high pitching rate, plenty of nutrients, low alcohol beer, etc.
You can use finings to clear the beer and dumping the yeast in the conical is key. Pasteurization is not required...the only reason a lot of breweries do this is to kill their yeast. If you are bottling, you do not bottle condition. You condition and carbonete in a keg or bright tank and then transfer to kegs through a filter.
Generally smaller breweries do 1-2 batches a day. Figure you are brewing 5 days a week and you've got yourself about 8 different beers every week, which would require 16 fermenters if they went through 2 weeks of fermentation.
But you are right that you would need to buy more equipment. Good thing sanke kegs are fairly easy to come by if you have the right connections (and no, i'm not talking illegal.)
You cannot really make any money (especially considering your time) if you are brewing 5 gallon batches.