Logically, it sounds good, but legally, there are quite a few hurdles to overcome. First and foremost is the licensure requirements. USDA wants a brewhouse up to commercial kitchen standards and require inspections upon pretty much any major change - I would think this inspection would be required to be repeated every time your operation changes location. Plus, the operations requirements that preclude commercial brewing in a non-commercial space would present a difficulty in most states. For example Squam Brewing in NH (one of the more business-friendly states) is a one-man operation using the back of a barn on his parents' property - however he had to formally lease both the barn AND THE DRIVEWAY to be eligible to apply for a license. For a restaurant that already has a commercial kitchen, the fermenters and space for them would be the biggest investment anyway - they'd already have large kettles, high-btu burners, refridgereated/ventilated storage, etc.
In a non-food production industry, the idea of a portable manufacturing truck (possibly paired with a portable packaging truck) would be a great niche opportunity, but when you add in the USDA's requirements, state food requirements (which are ofter stricter), and top it off with alcohol laws, I'm not sure that this is feasible idea.
I would recommend looking into who has recently sponsored alcohol-related bills in your state and contact them directly. Don't ask how you should go about it - senators and reps don't have time for that....keep it simple, just ask "is there anything that would stop this as a possibility?"
Hmmm.....if you have several sites'-worth of equipment, I could certainly see a niche for a lease/rental market. For example, if a restaurant wanted to brew for several days straight and package up a large number of kegs to age (and then didn't need to brew for a while), there could be potential to: have them set aside space, install the equipment, get inspections/license, brew their stash (at which point, any brewing gear could be moved to another client location), ferment and transfer to kegs (at which point, the fermenters could move to another location. The main difference is that you're not trying to use the truck as your brewhouse - it's just a truck. It's on each location to have the space set aside, to obtain their own license and inspections, etc. - that way, you're just an equipment rentor. If you want to brew for them, I'd suggest offering a package that includes hiring you as a part-time consultant/employee (so you'd be using the equipment under their liability and license). Hmmm.....now my brain's starting to cook along a little bit on this idea......
