the issue with the miscalculations on this batch were the following:
1. New big kettle without water level markers
2. somewhat misjudged how much water was actually put in the mash in the beginning.
3. somewhat misjudged how much sparge water was used, but it was about the same as the mash volume.
4. once in the kettle, a quick volume calculation came out to 31L..was probably 26 or so.
5. I think the wort was a little too warm when taking the pre boil SG. it only showed 1.030. Add pretty much 10lbs of malt and sugar as well as almost doubling the hops for a supposed 31L batch.
I only took the next SG post boil with wort temp of 20 degrees. The supposed 31L preboil ended up being 23, SG 1.084, and almost double the original hops.
This was basically an "empty the kitchen cupboard" recipe that got out of control....I do hope it turns out though, as I'll make an all grain version.