http://www.ncsl.org/research/financ...me-manufacture-of-alcohol-state-statutes.aspx provides a summary of each state's laws. As near as I can figure out for California, where I live, section 23356.2 of the Business and Professions Code does not prevent me from brewing for a friend in their home. If that friend wants to pay me I don't see where that is prohibited so long as the limitation of 100 gal/single, 200 gal/multiple adults in that household is not exceeded. California state law appears to be aimed at limiting the sale of a product rather than the sale of a service. I don't know if there are regs associated with this statute or, better yet, case law.
If it were me and it was one time for a friend who wanted to buy the ingredients & give me a little something extra for my trouble I wouldn't think twice about it. More than that & I'd read up some more. Do your own research, seek qualified legal advice if warranted and make up your own mind.
That is an interesting way of looking at it and it actually makes sense. You are selling a service NOT a product. It reminds me of wealthy people who have "staff" like personal chefs. The chef is hired to prepare meals in a private home. The employer buys the food.....the chef is paid to prepare the food. The same could be said for brewing. The employer buys all the raw ingredients and the brewer is paid to brew the beer in a private residence. Heck....if you wanted to really get technical the "employer" could pitch the yeast and then you really have no issues.