I've no clue as to brewing with acorns, but as a kid I made acorn flour & used it in pancakes; I've even made a sort of acorn bannock with it. It's pretty labor-intensive though. You have to leach out the tannins. There are 2 methods: hot & cold. I used the hot method described in Wildwood Wisdom by Ellsworth Jaeger; but WITHOUT using the wood ashes. There's also the cold leaching method, but that takes a few days.
Either way, it's a LOT of work, with little usable product. Though, if the boiling removed the oils along with the tannins, you might be able to use the acorn flour as an adjunct in a brew. You might get more flavor out of it if you toasted it in the oven, not sure though. You should use White acorns though, red are way too tannic.
Regards, GF.
I was always curious about this. As a kid I read "My Side of the Mountain" many times. It's a story of a boy who left home and lived on some family property in the Catskills of NY (IIRC) and one thing he did was make acorn flour. We have many acorns in our area and I've tasted them more than a few times, but never imagined they would actually make a decent tasting flour.
So maybe the part I missed in the book was how he got the tannins out before eating it. I *think* he soaked the ground up acorns in something and then saved the sedimentation and dried it to make a flour of sorts, but I may be confusing with some other process for something else. It's been a while since I read that book. (The movie was not nearly as good.)