Grain Absorption

Just sorting out some notes from my first brew and needed some help with grain absorption. Given the below variables;
-10.2 pounds of grain
-4 gallons of strike water
-2.75 gallons of first runnings
-.25 gallons of MT dead space

Secondly, do grain absorption rates change based on grain, strike, etc.

I find that if I calculate grain absorption at .12 qt./lb. it’s pretty darn close.  It does vary a bit with crush and grain type, but not enough to worry about.

+1

I get around 12% also.  Looks like you got ~10% absorption, which is certainly an acceptable number.

.12 is pretty spot on for me,too. At least plenty close enough.

I’ve been getting .14 but I count that as “in the range” of acceptable.

How are you getting my absorption at 10%?

Absorption Rate (gal/lb)

Strike Water Added - First Runnings Collected - Loss To Tun = Volume Absorbed

4 - 2.75 - 0.25 = 1

Volume Absorbed / Grain Weight = Absorption Rate

1 / 10.2 = .098

For clarity, the absorption rate being referenced above is in the .12 gallons per pound range, right?  I have always just figured a pint per pound for a horseback estimate.  I have so little dead space as to not be worth calculating that part, but YMMV.  Maybe a half cup to a cup, at most below the pickup tube.

same here…almost no dead space and that’s how i have it configured in beer smith. my absorption is .12gal/lb…so i collect precisely the amount of projected wort every time.

I get 0.10 GALLONS per pound.

Yep, gal/lb

I was wondering if my system was freakishly efficient for a minute there.  I actually get .10 gal per pound too. 0.15 gallons left for mash tun deadspace.

Thanks gents.