In a fit of boredom at work, I decided to try to figure out the maximum amount of grain I could use for a 5 gallon batch. It’s not the most useful information, but I was bored, so here’s my answer and the assumptions I made to get it.
No sparge mash with a minimum of 6.5 gallons or 26 qt of liquid wort collected.
1.5 qt water/lb grain
.8 qt water absorbed/lb grain
This results in a maximum of 0.7 qt of wort collected per lb of grain.
So 26 qt x 1 lb/0.7 qt = 37.14(and lots more numbers after the decimal) lb of grain max per batch.
With the amount of sugar left in the mash, I’d sparge two additional batches out of this. Could be a fun group brew day.