Biggest Mash Yet

Ok, so we're on our 5th AG, and b/c of various constraints we've decided to do a partigyle that will give us 5 gal of high grav and 10 gal of low/medium grav (by our standards). I'm not worried at all about the partigyle part of this, actually.

We have a 70qt Coleman eXtreme MLT. That's 17.5 gallons. I'm thinking 40 lbs of grain is our theoretical max in this MLT. At 1.25 qt/lb the "can I mash it" calculator says it will take 15.7 gal.

My question: are we leaving enough space? Are we really going to be able to do 40lbs in a 70 qt cooler at 1.25 qt/lb?

according to a "Can I mash It" calc that I found, looks like it will be fine, I have done 30 lbs in my 70 qt coleman xtreme and had PLENTY of room

I have a coleman extreme also...though i have nevr done a grain bill over 15 pounds it seems i could easily fit 40 lbs of grain in there

Take a look about middle post for 40.75 pounds in a 15.5 keg.

BW Brewing

It really could of gotten messy!!

From what I understand 55 lb of grain takes up about 10 gallons of volume uncrushed.

B-Dub said:

Take a look about middle post for 40.75 pounds in a 15.5 keg.

BW Brewing

It really could of gotten messy!!

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Ok, how much would you say it overflowed?

If the "Can I Mash It" calc is correct, I have enough space. I just want to know if we're going to be able to stir the mash, or if we're not leaving enough room.

Well the 40.75 pounds and 1.25 qt per pound, I think the end water to grain came down to 1.15 or so, with the foam you get with a good mash came right to the top of the 15.5 gallon keg and some foam came out on the floor.

When adding the grain I did it in stages so it was easier to mix. The top portion of the mash was a SOB to mix. Every 15 min I like to give the mash a stir and that ended up with some liquid loss on the floor. Not much though.

Still looking back the next time the RIS is brewed the mash will need to come down to 37 or so pounds and the H20 is coming down to 1.1 qt/pound.

I hope that helps.

Well I have been there too and will not put that much in a mashtun again. I always brew 10 or 12 gallon batches. I now use 2 cooler/mashtuns if I am making a big beer. I actually would like one big round large diameter cooler/mashtun but they don't make them. Maybe some day I will find a large vessel and insulate it myself. Then I would also need 2 HLT's, burners and propane so that may be why I have not bought a bigger mashtun.

Just for the record, and for anyone following in my doubting footsteps, we did it. We mashed 40lbs in the 70qt Coleman eXtreme. I wouldn't put much if any more in there, so I'm glad I didn't trust the "Can I Mash It" calc and left some room to spare.

Yes, it is very hard to get it all in there with no doughballs but it can be done. I know the efficiency suffers a bit but it does make large brews possible.

WBC said:

Yes, it is very hard to get it all in there with no doughballs but it can be done. I know the efficiency suffers a bit but it does make large brews possible.

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Actually we didn't have any doughballs and our combined eff was a whopping 90% (I'm a bit unclear on the math behind this, but worked it out with Beer Smith). Of course we mashed overnight, so I'm sure that helped the eff.

With three guys it was pretty easy to slowly pour the grain into the water in the MLT from a large rubbermaid tub while one of us stirred.

Here's the numbers:

First Runnings: 7.4 gal runoff at 1.095 preboil (5.25 gal at 1.132 post 90 min boil)
Second Runnings: 11.8 gal from two batches at 1.032 preboil (9.9 gal at 1.046 post 60 min boil)

Very nice. What did you brew?

Ooompa Loompa said:

Very nice. What did you brew?

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The high grav one started out being an IIPA SMaSH using Briess 2-row Pale and Nugget but b/c the grav was a good bit higher than I anticipated, it's more of an American Barleywine, though it exceeds the grav for that too. If I'm worried about anything (and I'm not 'cause I just had some homebrew) it's that this beer won't be bitter enough.

We topped the mash with 1/2 lb of Crystal 120L and used a variety of hops to make a smallish ESB with the second runnings.

Sounds cool!

Most I've done was 29 lbs in my 48 qt Igloo... looks like your numbers are right on par with that.