Grain Volume in Mash Tun

[dogismycopilot]

Can anyone tell me how to calculate the volume that dry, crushed grain will take up, once it is mixed with water in the mash tun?

I'm trying to figure out how much water my mash tun will hold, with a given amount of grain.

Full story... I'm attempting my first 12 gallon batch, in my 10 gallon cooler mash tun / 15 gallon kettle set up. For some reason, even with that equipment specified in Beersmith, it's telling me to add over 11 gallons of water to the cooler/tun (including mashout.) So, I'm trying to scale it back as little as possible. I'm not sure how much water the 10 gallon cooler will hold, with about 21.5 lb.s of grain. (Doubling up the BCS Kolsch recipe.) I've scaled the stated batch size down to 11 gallons (and even tried 10), but that just adjusted the sparge volume. Changing the water-to-grist ratio is the only thing I'm finding that will bring the water volume down, but I can't tell how low I need to be, since I don't know how much room the grain will take up.

Any suggestions?

[maxwell]

You should be able to fit 8 gal of water and 30 lbs of grain. That will be a very thick mash (~1 qt/lb). If in doubt, just plan your strike water temp for 1-1.1 qt/lb and you should be fine with your amount of grain. I used to do 15 lbs and 4 gal in my 5 gal igloo all the time. Hope this helps. Probably someone else will actually know the formula for grain volume in the mash.

[snowcapt]

Average grain absorption is 0.15 gallons per pound. It can vary between 0.1 and 0.2
Hopefully that helps ya get to where you are going.

[labguy]

check out this site-seems to be pretty accurate for me. It's the 'can I mash it' calculator part way down the page

http://www.rackers.org/calcs.shtml

cheers

[dogismycopilot]

Thanks very much for the replies. I've always done a mash out, but it looks like I'll have to skip it this time. No big deal, I guess.

To be fair to Beersmith, my OP wasn't entirely accurate when I said that I scaled the batch back down, and it only adjusted sparge volume. I originally scaled the recipe to 12 gallons, and bought my grain before noticing the mash tun capacity problem. So, rather than scaling the recipe again (which would affect the amount of grain), I was just adjusting batch size, to try to make it fit. This, of course, changed the OG, IBUs, etc, so I'll just try to find a happy medium, and get as close as I can.

Prost!

[TheeMattSmith]

+1 for that website above. It works wonders, I had a similar situation a bit ago and that site saved my brew day