Hello, Retro. I'm more than willing to send you some bokashi "bran" and instructions on how to use it, if you'd like. For the record, I've given away literally hundreds of kits, held classes and had booths at fairs. It is extremely cheap to send, and I'd just like to hear your experience with (especially) spent grain.
About the spent grain connection: larger breweries are usually locked in to removal contracts. They get charged twice for the grain: once on delivery, once on removal. The grain company then charges farmers a third time to buy it as feed.
I happen to be fortunate to be a lapsed member of the Bloatarians, and to be very close to Dan Listemann's shop; Dan's a great guy, and very approachable. I suspect that as his brew takes off, the free grains will become a thing of the past, but right now he's been very willing to share them with me. I've picked up 5 times now, between 30-50 gallons a time. Again, I don't expect this to last forever.
It doesn't hurt to ask, but don't be surprised if they're locked in. A local brewery, Mt. Carmel, has a contract, but was willing to find out if there was any leeway with the removal person, but I didn't want him to go through the trouble. But that tells me they're willing to work with folks.
Re: asking. It's possible to get all sorts of free stuff for the garden by asking, especially things others regard as trash. What got me started w/bokashi was being inundated with fish parts from a local fish market; I was picking up and processing as compost, got sick, and my wife kept picking up. At the end of the illness, I had 50 gallons of fish parts, and had to figure out how to deal with it, quickly. I made a fish emulsion of that stuff, using molasses and compost, which negated the potential smell through microrganisms. It worked, I tried to figure out why, and arrived at the bokashi method.
For the classes I have, I give away buckets I pick up from local cafeterias and delis. Any place that uses lots of pickles usually has them. They throw them away.
I'm involved with a greenhouse therapy program that picks up culled produce from supermarkets.
Just ask. Explain what you want it for. You'll know within seconds if you're getting through. Honestly, I've never been turned away. However, I've talked to quite a few business owners who are reluctant at first because someone else had asked and then dropped the ball. Make sure the expectations are clear, form a plan with them to minimize the grief it causes them, and stick to it. And share some produce.
Let me know if you're interested. Of the 100's of folks that have used the method, only 2 so far failed on the first try, and that was user error; however, due to the peculiar nature of spent grain, in terms of volume, composition and moisture level, I'm nervous that it's going to be more difficult, and would love to hear how it went on your end.