I just read about a system of using left over brewers grains to make food.
The company is called Rise Products
Rise Products From their web site
"Every batch of flour is sourced from craft breweries in New York City and embodies the unique flavours and aromas from local ales, lagers and stouts."
John Daley Bendigo, Australia
The Enemy of progress is the hope of a perfect plan
You can make "small" beer from "spent" grain, so this flour might be good for that as well!
Solar or rocket drying these spent grains might help at the household level.
Jiuqu balls (https://en.m.wikipedia.org/wiki/Jiuqu)could be a good way of processing the remaining carbs into more booze, and from there into vinegar.
My friends at Carriage House Farm are doing some thing like this.
They call their line of vinegars Madhouse:
Richard Steward runs Carriage House Farm and already mills grain for himself and other local farmers, I wonder if he has considered milling the spent grains he gets from our local Mad Tree Brewery.