Well, I'd say either have one of them take the time to learn to brew beer, and just give them a brew beer skill for skill checks, or allow them to seek out and recruit an NPC that could do the brewing for them. Then, just have most of the group's work go towards keeping the operation a secret, and setting up distribution, and possibly a few speakeasies. You know, the fun stuff.
The party should rarely have to do the monotonous busywork, and even if they have to do it, the game shouldn't focus on it for long.