Hi Joe, welcome to the forum!
There are plenty of people who have set up businesses focused on homebrewing, there are a few who have moved from Home brewer to pro brewer as well.
I think any of the suppliers of homebrewing equipment started off as homebrewers and decided to turn their hobby into a business. A few of the micro breweries were set up by homebrewers so maybe calling them to see they are interested might be the way to go.
So why choose homebrew as the topic of your documentary?
Best of luck with it and I'd love to see it when it's done.
Please do not hesitate top ask any questions on here some of the guys here know everything <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="

" title="Very Happy" /><!-- s:D -->