I have read that normal grain absorption is 0.12 gallons per pound of grain. I recently made an oatmeal stout with a 10.25 pound grain bill. Using this formula I set a mash-in/out and sparge schedule using a total of 7.25 gallons of water. The intent was to lose 1.25 gallons to absorption and end up with 6 gallons to boil, with an ultimate total of 5 gallons in the primary.
There appeared to be only about 5 gallons and some change after mash-in/out and sparging, however. Am I way off when calculating absorption? My mash tun did not have dead spots. All in all I would say maybe a half of a cup of wort remainded in the tun after all was said and done.
The only thing that comes to mind as a possible cause would be that my manifold is slotted on the underside, although I can not really see a reason why this would be an issue. I should also mention that my volumes were similarly a bit off with my previous batch, which was a pale ale. Any ideas?
There appeared to be only about 5 gallons and some change after mash-in/out and sparging, however. Am I way off when calculating absorption? My mash tun did not have dead spots. All in all I would say maybe a half of a cup of wort remainded in the tun after all was said and done.
The only thing that comes to mind as a possible cause would be that my manifold is slotted on the underside, although I can not really see a reason why this would be an issue. I should also mention that my volumes were similarly a bit off with my previous batch, which was a pale ale. Any ideas?