Originally Posted by senorfartman
Wait I think I've figure out what I've been doing wrong and it's so simple.
When I read batch size in the promash recipes, I took that as for what's going into the fermenter i.e. 10 gallon batch size meant 10 gallons of wort in the fermenter.
Unless this theory is wrong also, technically what I was doing was correct. When I halved the batch size to 5, I was getting 5 gallons of wort but I boiled off 1.5 gallons of it which would explain my low volume.
Am I correct on this? Apparently I'm still at the noob stage
No batch size is what goes into the fermenter.
Ok here is what you have done.
You used 10.75 ponds of grain, mashed with 3.5 gal, sparged with 6 gal for a total of 9.5 gal used. Going with the absorption rate of .1 gal per pound you will lose just over 1 gal to the grain. This (if the tun drains 100%) gives you 8.5 gal into the kettle.
Depending on what size the kettle is this should have been easy to see if you were even close to that or not.
You are missing something somewhere and until you figure it out we can't help you.
It comes down to "know your equipment and system". Even if this was your first brew you ever did you should know what you are putting in and what you are getting out.
So, the way I see it is.
1. you had a stuck sparge.
2 you messed up your count thus you did not use 9.5 gal
3. you have one hell of a burner and are getting like 60% boil-off rate (very unlikely)
Those are the only things I can think of that it could be. Either one or a combo of all three.
I repeat... "know your equipment and system".
Figure out and mark the kettle for gallons.