Option 1: suck it up. By posting the recipe online, it's in the public domain, and anyone can use it.
Not entirely true. However, the home brewer would have to show that the commercial brewer did not know it was posted online and did not get the recipe from the online copy. If that could be shown, the home brewer might be entitled to some degree of remuneration.
If a brewer wanted remuneration in such a case, he or she should talk to a lawyer. There are likely other legal theories that could apply also. All things that would require talking to a lawyer. The real question here then becomes do you go to a lawyer or what do you do instead.
Option 2: Publicize it. Call the local media and tell them what happened. Make the brewery publicly apologize, and make them put your name on the beer. See if you can get your brewery name on the bottle as well.
B
You could do that also... Except that is like running out and crying to Mommy.
... In a situation like this, I would be classy. I would contact the commercial brewer and say, "Guys .... you asked me to prep it, I gave you the recipe, you said it was too expensive, and then you went ahead and did it anyway. There must have been a miscommunication here somewhere. I feel like I have been wronged, is there any way we can clear this up?" If the commercial brewer is cool, they'll realize they screwed up (hell, if they're big enough it could be as simple as the right hand not knowing what the left is doing), and they'll come up with at least a decent apology.
That is, give the commercial brewer a chance to eat crow first, before you try to force feed it to them.
- M
PS: Crow is great with a mean BBQ sauce.