First decoction mash

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tkone

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so i'm about to embark upon my first decoction since the temps in nyc are supposed to drop to the low 70s which means i won't die of dehydration when i run the stove in my apartment for about 4 hours straight.

but, onto the decoction, i figured i'd make a VERY simple vienna lager. (yeah, color estimate is off, eh)

11 lbs vienna malt
2 oz hallertau 3.5% @ 60
2 oz hallertau 3.5% @ 15

(so i guess this is SMaSH...)

but now, onto my concept of decoction. i'm using a 10 gallon rubbermaid drink cooler and i'm doing the triple decoction schedule that's in beersmith as "triple decoction, lager" (since, hey, it's a lager!) and this is what i think it's asking me to do:

5.5 gallon recipe total, calculated out using my standard boil-off/evap rate

Dough in: I put 9.9 qt of water @ 70F in the cooler, then add the 11lbs of crushed grains stir well and let it rest for 15 minutes.

Acid rest: I put 6.88 qt of water @ 169.8 F into the cooler, stir well and let rest for 20 minutes at 105 F

Protein rest (is this even necessary?): I remove 3.35 qt of the mash (it should be very thick, right?) and bring it to a boil for 5 minutes, then I add the boiling mash back to the mash tun and stir super well and let rest for 10 minutes at 122F

Dextrinization Rest: I remove 7.73 qt of the mash and boil it for 5 minutes. Then I add this back to the rest stir super well and let rest for 20 minutes at 155 F

Mash Out: I remove 5.55 qt of the mash, boil it for 5 minutes, and then put it back in, stir super well and rest for 5 minutes at 170 F.

drain, sparge, boil, etc just like you would for any other lager, right?


Also, when I add the boiling decoction back to the mash, that should cause the temp to increase, right? I'm not using any fancy HERMS or RIMS or even a direct-fired MLT.
 
Also, when I add the boiling decoction back to the mash, that should cause the temp to increase, right? I'm not using any fancy HERMS or RIMS or even a direct-fired MLT.

Yes, the decoctions bring the temperature up to the next rest. This is why it is important to have the correct decoction volumes.

Couple things...

Every decoction you pull (except mash-out decoction) should have a rest at 158°F for about 10 min. prior to boiling.

While boiling the decoctions, stir the crap out of it (otherwise, scorched grains).

Your acid rest may be unnecessary, but probably wouldn't hurt to do it.

The protein rest may also be unnecessary... actually it most likely is unnecessary. Unless the vienna malt is 6-row barley (Briess), you don't need the rest and may harm the beer by doing it. If it is 2-row vienna malt (e.g., Weyermann), I'd do the Hochkurz style rests here. Do one at ~140-142°F, then up to 158°F.
 
awesome.

so i should do a rest at 158 for 10 minutes before bringing up to a boil, and stir the crap out of it so it doesn't stick.

yeah, this is weyermann vienna, so you're saying:
dough-in (70 F)
acid rest (105 F)
hochkurz (140 F)
dext (155 F)
mash out (170 F)?

thanks for the help!
 
awesome.

so i should do a rest at 158 for 10 minutes before bringing up to a boil, and stir the crap out of it so it doesn't stick.

yeah, this is weyermann vienna, so you're saying:
dough-in (70 F)
acid rest (105 F)
hochkurz (140 F)
dext (155 F)
mash out (170 F)?

thanks for the help!

More or less, yes. I'm big on the "why's" of brewing, so I'll explain that the rest at 158°F for the decoctions is so that alpha amylase can break down starches that beta-amylase can't break down. Then, when they're put back into the main mash, they get broken down further by beta amylase into simpler sugars. Without doing this (like in a step-mash), these starches wouldn't get broken down at all... at least until the dextrin rest, resulting in a less complex wort.

You don't really need the dough-in. You could start at the acid rest. Heck, you you probably don't even need the acid rest unless you need/want to do it for your mash pH. And since the mash-out decoction doesn't do much of anything besides raise the temperature, you could even direct-heat it or infuse with boiling water up to mash-out temp and skip that decoction as well. This would leave you with a single decoction from ~142°F to 158°F (not 155°F unless you want to maximize attenuation).

When I do decoctions, I usually do a single decoction like above. But I rarely do decoctions anymore since I found little if any difference in the final beer between doing a decoction and step-mash.
 
Have you checked out by Kaiser?

You will also need to watch parts 2 and 3.

I found it very helpful.

I also think that menschmaschine's comments were very helpful, but a picture is worth a thousand words.

-a.
 
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Im curious how this method does not cause tannin extraction. Im currently reading up on decoction mashing and this is the most confusing part for me. I have read in so many places that when adding water that is too hot, like sparge water, it can cause tannin extraction. So when you boil the decoctions, how does this not cause tannin extraction from the grains?
 
Im curious how this method does not cause tannin extraction. Im currently reading up on decoction mashing and this is the most confusing part for me. I have read in so many places that when adding water that is too hot, like sparge water, it can cause tannin extraction. So when you boil the decoctions, how does this not cause tannin extraction from the grains?


You need to do a little more reading. High temperature alone does not result in a tannin problem. It is the combination of high temperature and high pH that does. Oversparging causes the pH to rise to unacceptable levels because the buffering power of the mash has been diluted. Decoction boils are done with thick mash portions at low pH so there is no tannin problem.
 
I recently did a decoction and I can tell you what I learned.

1.) The decoction affects the color. A LOT. This would actually make your beer more to style in this case.

2.) The decoction affects your efficiency. Positively. I think its because once you rest the grains at sacchrification temps, the sugar become available, but are still kind of chunked in the grains. Boiling them breaks these chunks. Just my theory.

When you figure your volumes, add a little extra to each decoction. Then, when you add it back, stop where you want. WIt for the rest to cool down to the same temp and then chuck it back in too. You really don't want to come in low and have to do something drastic.

Good luck!
 
I agree that the low temp dough-in could be skipped. It will just take up time imo.

A 20 min acid rest isn't going to do much of anything except take up time. It takes a long time for any significant pH drop. But you have to dough-in at some temp.

A short protein rest is probably fine BUT are you going to be able to pull the decoction, heat it to 158* F, rest for 10 min, then heat it up to a boil (without scorching it, so you can't go too fast), boil for 5 minutes and then get it all back into the main mash in any reasonably 'short' period of time? IMO, a 15-20 min protein rest would be OK but a 60 min one could be too long. If you've already rested for 10 min before you pull the decoction it could easily reach 60 minutes total rest time before you get that decoction back in.

You could dough-in (thick) at protein rest temp, infuse up to the maltose rest temp (~147* F), decoct up to the dextrinization temp (~159* F), and then either direct-heat/decoct up to mash-out. If you do a decoction to get up to mash-out, they are often just wort, no grain.

FWIW and IME, if you do the Hochkurz Decoction don't rest too long at the maltose rest (on my system would be ~20 min). Viennas shouldn't be too 'crisp' but yet still fully attenuated with a gentle creaminess.
 

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