# Calculating Grain Absorbtion

I just want to check to make sure I’m doing this right:

8.75lbs of grain.
7.5 gallons of water through the mashtun (strike + sparge)
6.16 into the kettle

So, the difference is absorption - 1.34 gallons, or .153 gallons/lb (which seems high compared to what I’ve read)

That’s the way to do it right?

I think I previously calculated it just based on the strike water and i got a slightly lower number (.128 gal/lb).

Further, I did another batch today, same size grain bill but less water (7.125 gal) and my absorption was .128 when I figured it based on total water through the system.

Thoughts?

Thanks!

That may not all be due to absorption, how much is left in your mash tun? At the end of the day it’s all considered a loss and needs to be factored in in your water calculations. My losses to absorption and my minimum dead space in my mash tun works out to ~.12 gallons/pound.

I like to use JT’s Mashwater3.3.

http://suburb.semo.net/jet1024/beer/sof ... tware.html

If you’re losing more than 0.125 gallons per lb of grain I would let your mash sit in the tun for a while after draining and then scoop out the grain and see what’s in the bottom.