Imperial Stout water:grain ratio question

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Salt

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Hey guys,

Im planning on brewing an imperial stout based on a recipe I have for Great Divides Yeti Imperial Stout. However when plugging my recipe into Brewmate, I am getting some weird figures for Sparge volumes and temps.

I have a 45Lt chilly bin Mash Tun, so should be able to squeeze it all in...but based on the brewday info (below), and on a ratio of 3L:1kg it is telling me I need 33Lts Strike water (total mash of 44Lts, with 11kg of grain). However as Im only doing an 18Lt batch, it then says I only need 0.6Lts of Sparge water at 623c.....WTF?

Do I not sparge an Imperial Stout of this size? Do I need to adjust my ratio? I have never brewed a beer close to this size, so if anyone can help, it would be greatly appreciated.

Do I need to drop my batch size ??

Cheers!

See pics attached for Brewday screen shot and Recipe screen shot

RISa.jpg


RISb.jpg
 
Due to your high OG you're chasing, you're adding plenty of grains to the mash. Brewmate is telling you how many litres are needed to make 18Ltrs in the end. So you are using almost all the water in the mash at 3:1. You won't be able to go much higher as there's not enough water.
At 2.5:1 ratio, you would only be using 27.5Ltrs in the mash and have 6.11Ltrs to sparge with.
To run at 3:1 and have extra sparge water you will dilute your wort and will need to boil longer to achieve the OG you want.

Does this make sense?
 
Nibbo said:
Due to your high OG you're chasing, you're adding plenty of grains to the mash. Brewmate is telling you how many litres are needed to make 18Ltrs in the end. So you are using almost all the water in the mash at 3:1. You won't be able to go much higher as there's not enough water.
At 2.5:1 ratio, you would only be using 27.5Ltrs in the mash and have 6.11Ltrs to sparge with.
To run at 3:1 and have extra sparge water you will dilute your wort and will need to boil longer to achieve the OG you want.

Does this make sense?

Yeah that makes sense and I thats kind of what I thought...Thanks heaps for clarifying!

I guess im not sure what direction to take for this recipe; is it best to reduce the ratio and sparge with a small amount or simply no sparge for the Stout and run off a separate sparge parti-gyle style and brew a smaller stout/porter with that?

Any advice? What have other people done, surely Im not the only person who has been in this situation?
 
So i've played around with the recipe a touch...and I am happier with it now;

I have dropped the OG down to 1.103 (which has dropped about 800g from the grist) and have increased the boil time to 90mins...so I can sparge with a little more and boil down as you have suggested.

Now I have a 25Lt Strike volume and a 9Lt Sparge. Is this suitable?

Any other advice?
 
I can't comment specifically on your system but I find I only get about 60% efficiency on my system when I try to make really high OG beers.

You can simply have some LDME on hand to correct your gravity and in that kind of beer should make little difference.
 
I'd say go for it. Best way to see if it'll work is try it out. You'll still make beer in the end whether it works the way you wanted it to or not.

I'm all for trying something out for yourself and learning along the way.

Hope it all works out the way you planned...

Cheers
 
Just make sure you realize that you are going to lose about 1-1.25 L per kilo of grain due to absorption. So, for the original recipe, you would probably lose 11 - 14 liters of water. Also, even though you have 11 kg of grain plus 33 liters of water, doesn't necessarily mean that you will have a mash volume of 44 liters.

If you add 33 liters of water to the 11 kg of grain, you should lose around 12 liters and be left with 21 liters in your kettle. On my system I would sparge with 15 liters to end up with 36 and boil for 90 minutes, losing around 15 liters. for a 21 liter batch.

Hopefully this helps a bit. Also, as previously mentioned, the bigger the grain bill is, the lower the efficiency, so you should have some DME on hand to make sure you hit your target OG.

Cheers!
 
OregonBrewer said:
Just make sure you realize that you are going to lose about 1-1.25 L per kilo of grain due to absorption. So, for the original recipe, you would probably lose 11 - 14 liters of water. Also, even though you have 11 kg of grain plus 33 liters of water, doesn't necessarily mean that you will have a mash volume of 44 liters.

If you add 33 liters of water to the 11 kg of grain, you should lose around 12 liters and be left with 21 liters in your kettle. On my system I would sparge with 15 liters to end up with 36 and boil for 90 minutes, losing around 15 liters. for a 21 liter batch.

Hopefully this helps a bit. Also, as previously mentioned, the bigger the grain bill is, the lower the efficiency, so you should have some DME on hand to make sure you hit your target OG.

Cheers!
Thanks for the advice! I think this will be a brew where I have; extra sparge water if needed and extra DME on hand and take a lot of readings along the way to determine where I am at.
Cheers!
 
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