BIAB Decoction

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JCasey1992

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Hi all!

I am planning on brewing a German Hefeweizen in a few days and have a question. I am planning on trying my first decoction mash. I plan to use a single decoction. I have done a lot of research on this and just want to be certain I am understanding the process correctly.

Based on the research I have done, my understanding is that I bring the temperature up to 113 - 131 degrees F for the protein rest and wait about 15 minutes. From there, I would pull about a third of the grist making sure to keep enough liquid so I can avoid scorching the grain and bring it to a boil in a separate vessel. Once I boil for 20 - 30 minutes, I would then return it to the original vessel and bring it to the mashing temperature for an hour and proceed as usual.

Is this correct? Also, if you have any other recommendations please let me know.

Casey
 

Kent88

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I've always heard that brewers should pull one quart thick mash per pound of grist for their decoctions. Make sure you're kettle is big enough for the decoction to be stirred comfortably, it is really thick and so you'll probably need a bigger kettle than you think. 131F might be a little warm. On the way to boiling, you can stop at alpha sacc' rest temps for a little bit, like 15 to 30 minutes. Stir like a madman.

When I was making my first decoction mash, I found this helpful.
 
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JCasey1992

JCasey1992

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JC - do you get Zymurgy magazine? It is a benefit of AHA membership (American Homebrew Association). There is an article in this month's issue on decoction mashing using BIAB. It is written by Gavin Conroy. Conroy, although a bit of a 'left footer' appears to really know his stuff :) :)

not sure if this link will go without signing in ... http://digitaleditions.walsworthprintgroup.com/publication/frame.php?i=368487&p=&pn=&ver=flex
Thank you. I currently do not get Zymurgy magazine as I am not a member of the AHA. Assuming it isn't too much money for a broke college student such as myself, I will definitely sign up.
 
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You will very likely get some of the same info right here from "GavinC" who is rumored to be tight with this Conroy fella.
 

bigplunkett

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What i do when i decoct is pull out a quart of grain per poind and strain off the liquid, put it all on a pot and bring it ti a sacc rest for 30 min then j bring to a boil and do so for 30min, stir ,stir ,stir and keep stirring so u dont scorch. Add it back in to your mash and it should bring the temp up close to sacc rest . I make sure to stir it in then proceed as normal. Exspect better then normal eff and a beer that is dryer.
 

dmtaylor

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When I do BIAB decoction, I ignore the bag and just mash and boil in various large pots and kettles until the very end when it's time to runoff, then dump the whole lot into a bag and continue the runoff (and for me, sparge) as normal.

By the way.... skip the protein rest. With all 21st century malts, it's likely hurting your body and head retention. Either aim lower at 105 F or go way up to like 140 F for your first decoction, and skip the protein rest range.
 

Kent88

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By the way.... skip the protein rest. With all 21st century malts, it's likely hurting your body and head retention. Either aim lower at 105 F or go way up to like 140 F for your first decoction, and skip the protein rest range.
So use the decoction to go from acid rest to beta sacc' temps? I wouldn't think you'd want to dough in right at beta sacc' temps as the beta enzyme denatures in the 140Fs and isn't that also too low for barley malt to gelatinize?
 

dmtaylor

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So use the decoction to go from acid rest to beta sacc' temps? I wouldn't think you'd want to dough in right at beta sacc' temps as the beta enzyme denatures in the 140Fs and isn't that also too low for barley malt to gelatinize?
Yup. I usually start either at room temp or heat slightly to 105 F, then decoct to jump to 140 F. The decoction will gelatinize the thick mash.
 

Nubiwan

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When I do BIAB decoction, I ignore the bag and just mash and boil in various large pots and kettles until the very end when it's time to runoff, then dump the whole lot into a bag and continue the runoff (and for me, sparge) as normal.

By the way.... skip the protein rest. With all 21st century malts, it's likely hurting your body and head retention. Either aim lower at 105 F or go way up to like 140 F for your first decoction, and skip the protein rest range.
@dmtaylor - sorry to ressurect an older thread - woud you care to elaborate on this or your current decoction process for a czech style pils? Picking up the grains today, and have been belly aching over whether to decoct or just do a single infusion. A recennt brulosophy case study has me tempted to keep it simple with an infusion.


If you know me, i like to keep my brew days short and simple, and as non-traditional as they get LOL. However, decoction doesn't seem that labour intensive if results are worth it. Your valued opinion is most appreciated.

Whats your ferment temp? Plan to use s-23. I get a pretty steady 60 degrees in my basment, but could push it to 45-50 in my porch right now.

How long to lager minimum? Again, I can probably get sub freezing in my garage at present.

Thanks in advance.

Grain bill is :
10lb pilsner
1lb vienna
.5 lb munich

Yeast is S-23

Got saaz for hops, but also considering magnum as a bittreing hop (any thoughts there)
 
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Barbarossa

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With that grain bill I would go straight to 152 or 154 and keep it there an hour. 150 if you want a dry beer.

For lagers, go at the lower range of your yeast for three weeks in primary. Then keg or bottle at 35f for four weeks.
 
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Nubiwan

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With that grain bill I would go straight to 152 or 154 and keep it there an hour. 150 if you want a dry beer.

For lagers, go at the lower range of your yeast for three weeks in primary. Then keg or bottle at 35f for four weeks.
Considering lowering the amounts of Vienna and Munich to about 5 % of the bill, after some further recipe investigating. I can throw the remnant grain in my amber IPA later.

So revised bill would be:
10lbs pils
.5 lbs vienna
.25 lbs munich
 
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dmtaylor

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@dmtaylor - sorry to ressurect an older thread - woud you care to elaborate on this or your current decoction process for a czech style pils? Picking up the grains today, and have been belly aching over whether to decoct or just do a single infusion. A recennt brulosophy case study has me tempted to keep it simple with an infusion.


If you know me, i like to keep my brew days short and simple, and as non-traditional as they get LOL. However, decoction doesn't seem that labour intensive if results are worth it. Your valued opinion is most appreciated.

Whats your ferment temp? Plan to use s-23. I get a pretty steady 60 degrees in my basment, but could push it to 45-50 in my porch right now.

How long to lager minimum? Again, I can probably get sub freezing in my garage at present.

Thanks in advance.

Grain bill is :
10lb pilsner
1lb vienna
.5 lb munich

Yeast is S-23

Got saaz for hops, but also considering magnum as a bittreing hop (any thoughts there)
I haven't decocted in several years now. If I did, like I said, I would probably dough in at about 105-110 F, let that sit for 5 minutes, then pull all the wet grain out (i.e., "the thick mash") then bring that to a boil for about 10-15 minutes, then return it to the main mash liquid, hope that it hits closer to the 140s, then let that soak for a good ~20 minutes, then repeat the decoction steps to hit 150s for another 20-30 minutes. Then could decoct a third time, or just call it good and run off and continue brewing as normal.

I don't fret over the exact process when I decoct, I just have fun with it, and it always seems to turn out very good regardless of the details. And I keep the steps short to just 10-30 minutes each so that I can get the batch done within ~5 hours so it doesn't take all day long.

I have never used S-23 but I have a pack and intend to try it in near future. I have heard that this is a fruity lager yeast and that it might perform even better at warmer temperatures than cold, sort of like a California steam yeast. So I will probably split a batch and try some cold around 50 F and the other half warm at about 65 F, just to see what it will do. And I suggest anyone else interested should (eventually) try the same experiment. Good for any yeast really, try different things and learn something.

Fermentation could be finished in a few days, or might take a few weeks. Let the yeast do the talking. I never rush my fermentations. If anything I leave them sitting for longer than I need. My advice for any beer, but for lagers especially, is to just leave it alone until you think it's done fermenting.... then leave it alone for another 3-4 days before even thinking about touching it or chilling it down. The yeast needs extra time after fermentation to clean up after itself. Just let it. Once you are certain everything is good and done and clean with no diacetyl, then you can chill it for as long as you like. About a week or two at icy cold temperatures is probably enough for most lagers. And even then it is probably optional, as long as the fermentation is really complete already anyway. I would never chill it down until I was very certain that the fermentation is 101% complete. Otherwise you could lock in diacetyl or sulfur or other nasty compounds and prevent the yeast from cleaning up.

Your recipe sounds good. Magnum is a great hop. Saaz is more hit & miss in my experience, probably depends on the source. Get the good stuff from Czech Republic.

Cheers, good luck, enjoy. :mug:
 

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