4 years is pretty ambitious… also, there’s a weird jump between homebrewing and commercial that I don’t even know how to traverse.
Definitely get into all grain… look into water treatment, yeast management, string together a bunch of beer. Perfect a few house styles- make a pale ale. Make another. And another. Compare notes, adjust and do another until you’ve absolutely nailed the style. Keep on making it while you do the same experiments with a stout. Over and over again, until you nail it. Eventually, you’ll have a library of “flagships” that you can knock out consistently.
I know this sounds like I’m being a wet blanket, but don’t be that guy who opens a taproom after a couple of years of homebrewing only to serve really bad beer. There are a few of those around and it makes me sad. If you really do want to go pro, you’ve got a lot of work ahead of you. I don’t know that 4 years is enough without also doing some formal education or apprenticeship. But hell, it should be fun to try to get there, so who am I to say anything against it…
