Imperial stout via reiterated mash in a 10.5 Foundry

[RyPA]

I am planning to do an imperial stout in the near future which calls for 20lbs of grain. My original plan was to buy the false bottom linked below and a grain bag and do a BIAB without the malt pipe.

This morning I got video on my youtube feed where the guy was doing an imperial in his 10.5 and he did a reiterated mash. I am now thinking I will do that instead & save myself ~$50 at the cost of ~1 extra hour of brew day time.

My question is, does it matter which grains I mash in the first or second mash? i.e. is it ok to mill all grains together and do a mix of everything twice, or should I keep dark malts separate and mash those in the second pass.

Thanks!

https://www.amazon.com/gp/product/B07G1B1YJM/ref=ox_sc_act_title_1?smid=A3J055FHBJJDOR&psc=1

 

[hottpeper13]

When I do this I combine all the malts because the liquor chemistry is easier to figure out. I don't use a program for my salts. I also use RO water and don't treat the sparge liquor.

 

[RyPA]

Have you done an imperial with ~20lbs? Trying to figure out water volume. I usually use 7.5-7.75 gallons for my 6g (keg) batches that have ~12-14 lbs of grist.

 

[Bobby_M]

I know you should be able to get 16 LBS in the malt pipe and what you can do is set he recipe for a 120 minute boil. Mash 16 pounds of base malt. When you pull the basket, sparge as much as needed for a preboil that will reduce down properly with a 120m boil. I'm assuming the remaining 4LBs or so is mostly roasty/caramel stuff. Once you empty the base malt out of the malt pipe, drop it back in and steep the roast/caramel in the basket while you're ramping up to a boil and pull it out before you cross 170F.

Alternatively, after the main mash is done, you can scoop out about 4LB of base malt and put it in a strainer over a bucket. Then replace that empty space with your 4LB of specialty grains and stir them in well. Extend the mash another 15-20 minutes. Then pull the basket and sparge. Add any wort in your strainer/bucket back into the boil after the malt pipe is removed.

Third idea. Get as much grain as you can into the malt pipe (grain fully mixed together) and then do a little side mash in a 2 gallon pot on the stove (or stashed in the oven) with no bag or anything. When you pull the malt pipe to sparge, just slowly pour the side mash into the top of the malt pipe, let it drain some and then sparge.

 

[RyPA]

I know you should be able to get 16 LBS in the malt pipe and what you can do is set he recipe for a 120 minute boil. Mash 16 pounds of base malt. When you pull the basket, sparge as much as needed for a preboil that will reduce down properly with a 120m boil. I'm assuming the remaining 4LBs or so is mostly roasty/caramel stuff. Once you empty the base malt out of the malt pipe, drop it back in and steep the roast/caramel in the basket while you're ramping up to a boil and pull it out before you cross 170F.

Alternatively, after the main mash is done, you can scoop out about 4LB of base malt and put it in a strainer over a bucket. Then replace that empty space with your 4LB of specialty grains and stir them in well. Extend the mash another 15-20 minutes. Then pull the basket and sparge. Add any wort in your strainer/bucket back into the boil after the malt pipe is removed.

Do the darker malts need a full 60 to convert sugars, or are they only adding color/flavor where 20 mins is enough?

Any advantages to the above method compared to just doing a reiterated mash/2 mashes?

 

[Bobby_M]

Do the darker malts need a full 60 to convert sugars, or are they only adding color/flavor where 20 mins is enough?

Any advantages to the above method compared to just doing a reiterated mash/2 mashes?

There is starch that can contribute in the presence of other malt's enzymes but it's like 25 gravity points per pound per gallon vs 35 of 2 row. If you put them in while you're ramping up to a mashout (170F), they will convert pretty quickly.

A reiterative mash is pretty low on efficiency because of how high the gravity is that gets trapped in the second batch of grain. If it were in a bag, it would be more recoverable during squeezing. The other efficiency loss is in time. Two 75 minute mashes is a longer investment.

The truth is, there are a dozen ways to slice this lemon.

 

[hottpeper13]

If you're holding out the darker grains ,why not do an overnite cold steep and just at that to the wort after sparge? Those grains are converted already and just contribute around 22 gu's /lb.

 

[hottpeper13]

To your volume question, use the normal grain absorption constant. Mine is .11 for MIAB and .06 for BIAB. Multiply the grain weight by the constant and that gives you the amount of brewing liquor that stays behind.

 

[tracer bullet]

I'm genuinely curious what extra efficiency is gained with a reiterative mash? I get the concept just wonder how much extra %age you get?

Sparging for me was anywhere from +5 to +10% efficiency, somewhat dependent on the grain bill and the water volumes. I'd guess reiterative is even more but kind of wonder. Does anyone know? I searched a little but didn't see any #'s.

Of course one could do both, and I'd definitely recommend it if you're searching for efficiency and seemingly have time to spend. Although... my sparging is usually a dunk sparge, I move my grain bag over to a pot. If you are solely running with the pipe that will be harder. Maybe consider trickling a gallon of water over the grain the 2nd time through, or a half gallon each time.

 

[RyPA]

I'm genuinely curious what extra efficiency is gained with a reiterative mash? I get the concept just wonder how much extra %age you get?

Sparging for me was anywhere from +5 to +10% efficiency, somewhat dependent on the grain bill and the water volumes. I'd guess reiterative is even more but kind of wonder. Does anyone know? I searched a little but didn't see any #'s.

Of course one could do both, and I'd definitely recommend it if you're searching for efficiency and seemingly have time to spend. Although... my sparging is usually a dunk sparge, I move my grain bag over to a pot. If you are solely running with the pipe that will be harder. Maybe consider trickling a gallon of water over the grain the 2nd time through, or a half gallon each time.

I think the consensus is that the reiterative mash hurts efficiency, as you are taking high gravity wort and mashing a new batch of grains and losing some of it due to absorption.

I’m considering doing what Bobby suggested: mash with the lighter malts (15lbs), when that’s done, remove ~5lbs of the mashed malt (squeezing it the best I can) then put the darker malts in a bag and steep that for 30-45, remove and squeeze out the precious liquid.

Is there any harm in mashing the lighter malts for 1.5-1.75 hours, and is 30-45 minutes enough to get some points out of the dark malts, or should I give it a full hour?

 

[GoodTruble]

I've done this several ways, and I actually liked the cold steep overnight method the best and it yielded the best results. Your mileage may vary.

Alternatively, mashing the base grains first, and then removing and mashing the rest in a bag was my second favorite option.

Third, replace some base grains with DME.

 

[tracer bullet]

Is there any harm in mashing the lighter malts for 1.5-1.75 hours, and is 30-45 minutes enough to get some points out of the dark malts, or should I give it a full hour?

Nope, and yep.

People do overnight as mentioned, you'll get a more fermentable wort the longer you go but it's partly temperature dependent as well. It won't hurt anything though, and honestly I prefer longer mashes for Imperials so I can strive for a slightly lower FG.

As for how long as a minimum, it's the more the merrier but diminishing returns. 45 minutes will do a lot, but feel free to go longer (and don't sweat it if time gets short).

 

[Bobby_M]

Only issue with cold steep is you get no gravity out of it.

 

[RyPA]

Ok, I think I am going to go with the approach that Bobby suggested.

Recipe question - do you think maris otter will do anything to help an imperial stout, or should I just go with standard issue 2 row?

 

[tracer bullet]

I've gone to 2-row, I don't think I can tell a difference. Imperials are already expensive enough without unnecessarily over paying for a grain I'll never taste. Whatever it adds I bet could be substituted for a pinch of Munich or maybe Caramel 40 or something, which I include already.

That's 1 opinion only. I'd be interested to know if others could tell.

 

[RyPA]

I've gone to 2-row, I don't think I can tell a difference. Imperials are already expensive enough without unnecessarily over paying for a grain I'll never taste. Whatever it adds I bet could be substituted for a pinch of Munich or maybe Caramel 40 or something, which I include already.

That's 1 opinion only. I'd be interested to know if others could tell.

That's kind of where my head is at. It's a stout to start with, which I think would overpower subtle flavor differences provided by maris otter, in addition to that, it's a boozy imperial.

 

[GoodTruble]

Ok, I think I am going to go with the approach that Bobby suggested.

Recipe question - do you think maris otter will do anything to help an imperial stout, or should I just go with standard issue 2 row?

Man, I hate when Bobby wins. =c)

I always use some maris otter in my stouts. The impact may just be in my head.

 

[RyPA]

Hmm, maybe I’ll just do a full mash

This guy did 19lbs of malt in a 10.5 Foundry


I do also have a Home Depot igloo cooler mash tun, but not sure if that provides any extra bandwidth

 

[tracer bullet]

Honestly just pick a method and go for it. If you do the simple approach, there's a few things to keep in mind:

* You can add some DME to boost your final result, if you add 3lbs of DME it's something like 5 lbs of grain equivalent. I won't try to say if that's exactly it, but you can mix in some DME (or even LME) and bump your gravity / reduce how much base malt is required.
* You can always keep boiling until you get the gravity you are looking for, even if it means you end up with just 4 gallons or something. Do mind your hop additions if you think this will be needed.

 

[jerrylotto]

I JUST posted this to another topic:

When I mash high gravity worts, I tend to do it in two stages. Stage 1 is all base malt using 50% of the weight of the overall grain bill then sparge. I collect the sparge runnings separately in a different vessel and make it up to a full strike volume by adding first runnings to it (if necessary). Finally, I mash the remaining base malt and all of the adjuncts in that new "strike wort", holding aside a second sparge volume of water at 170F to rinse down the secondary mash.​