I’m in the process of setting up a HERMs system and need help determine what size mash tun would be best. I’m looking at a kettle that is either 12.75 (10-15 Gal) or 15.75 inches (20 Gal) in diameter. I like to brew both 5 and 10 gallon batches so I’ll be using any where from 8 lbs of grain on up. I’m not sure how to calculate what the grain bed depth would be. I’m concerned that if I go with the larger kettle I will have problems with some smaller beers, or if I go with a smaller kettle bigger beers will be an issue. Any help/suggestions is greatly appreciated!
The “Can I Mash It?” calculator here will help you determine what size beers will fit in each. My 10gallon mash tun will fit ~21lbs grain with 1.5qts water/lb.
http://www.rackers.org/calcs.shtml
About grain bed depth, if you have some grain, Measure a gallon of grain and weight it to get gallons/lb. My guess is around 6lb per gallon based on some buckets of grain at home.
The volume of those kettles is pi*radius^2 per vertical inch (in cubic inches) - or -
Small: 6.375^2 * 3.1415 = 127.67 cubic inches = 0.55 gallons/inch
Large: 7.875^2 * 3.1415 = 194.82 cubic inches = 0.84 gallons/inch
Sounds like I should go with the smaller size! Thanks for the help!
Here’s a good, quick and dirty picture:
Maybe a dumb question but does this calculator work for batch sparging too? I want to go to 20 gal batches and want to make sure I get a cooler big enough for batches up to 1.065 at at least 1.5 qt/lb, preferably 2.
Graham, this one might help, too.
Thanks Denny. That’s the one I was referring to. Mtnrockhopper above mentioned that one.
How big is your “Malt Coffin”?
Oops, missed the link above. The mash coffin is 152 qt. I’ve had 75 lb. of grain in it at 1.5 qt./lb. with room to spare.
I’m looking at 150 qt but they only come in green or white. No Blue so I don’t know what to do.
My dirty secret…my 152 is white…ssssshhhhh…
AAAAAAAAAAAARRRHHHHHHHHHhhhhhhhhhhhh!!!.. //sobbing//
And now we know the truth!
Amanda K needs more rows on her table/spreadsheet. 