I'm planning a Russian imperial stout for my next brew, which is going to use somewhere in the neighborhood of 23 pounds of grain. Should I just plan on using two mash tuns, or will that much fit in one of ours?
Wed, Nov 25, 2015 - 8:08am
#1
Mash tun: how much can they fit?
You'll be good with 23 pounds at 1.25 quarts per pound. Anything more than that and you would have to use a much lower mash to grist ratio, which will, of course, not provide as much wort.
I just brewed a Russian Imperial last night in one mash tun.
Seperate out your dark grain and add it when you are sparging... that's another way to get around a big beer with a lot of grain too. Plus you help not pull extra proteins you don't want in your beer anyway.
I'd save the hassle and just use two tuns. I like to mash a little bit of the darker grains to lower the mash pH.
Also, for future reference: http://www.rackers.org/calcs.shtml
See and I was thinking THAT would be the bigger hassle, doing two sparges
Ha, I see your point!
Even if you have to use slightly lower water/grain ratio, you can just sparse extra to make 23 lbs work in one mash tun. I like to put the black malt in the mash because it helps balance the alkalinity of the Chicago water. You should also plan to use a 2 hour boil to get the wort to the right concentration.
Alternatively, mash in with 20 pounds by cutting back your 2 row and buy 2 ponds DME.
Just so you're aware, the volume displaced by 1 lb of grain is ~0.08 gal/lb.
This means you can either do Water + 0.08*grain = total volume
or
total volume = Grain bill * (0.08 + (Mash thickness / 4 ) )
For what it's worth, I would consider two mashes with half the grain bill rather than an extended boil or splitting the mashes. Use all the strike water with half the grains, drain it, then take the first runnins (no sparging!) and use that as the strike water for the rest of the grains. This will have higher mash efficiency since it has a higher mash thickness, meaning higher conversion efficiency per braukaiser (and my findings concur) and still have a decent lauter rate (no sparge is typically around 80% for ~12 lbs).
You can then do a partigyle for the rest of it, or sparge still and combine runnings.
See my online calculator for more info http://pricelessbrewing.github.io/BiabCalc/
FWIW: I crammed it all in one tun and had a fairly stiff mash (and 23 pounds of grain). I had rounded up on the grain bill a bit, and my gravity was higher than I was aiming for. Same thing on my second brew this weekend, which was a pound less: I didn't bump the grain bill on that one and hit my target gravity on the nose.