Decoction Mash

Sun Oct 22, 2006 11:11 pm

or Doc Cock Shaun


OK lets start by saying that I am by ne means a expert at this, but i have done quite a few Decoction brews over the years, and I strongly believe there is absolutely no substitute for it at all, ever, no way. you will get some of the flavor profiles but you will never ever get the full benefit.

Ill list the benefits i find first then go into how i do it the normal way, then my express method.

So what is a Decoction mash, well basically its boiling the grains, now the first 1000 comments in the chat today was about leaching tannins from the mash because of the temp, well this is not so, because the thick part of the mash is removed, that is to say that your taking out grain only with very little liquor at all, because of this the grain pH will stay low, there really isnt enough (water) there to raise the pH , also the actual action of boiling the grain will reduce the pH (i think this is just why the Czec brewers could get away with brewing such a thin mash with very soft water with out ill effects) It wa salso mentioned about killing off the Enzymes, well the reason this does not happen is that as the grains get wet the enzyme is extracted and will actually be in the liquor, not so much in the grain, and what is left in the grain will not matter to much anyway.

Ok so whats happening when you boil the grains, the cell walls of the grains are being destroyed, making it easier for the enzymes to get to them. That is is, pretty straightforward, but because of this there are a few other things that happen, and the major advantage that i see is a cleaner ferment and a beer that clears faster, and i think this is because the Proteins are coagulating in the mash and being removed, rather than in the kettle


OK so how do i do it,

I have a 10 ltr pressure cooker, it has a big thick base, and a large SS conical shaped strainer that holds about 3 kg of Grain, So i take the strainer and fillit with grain and let the liquid run off, put the grain in the pot and raise it to the next step, let it sit for 10 mins then bring it to the boil, for Pilsners and darker beers i boil for about 15 mins and put it back into the mash tun, adjust the mash temp (because i always fall short) and do it again, I will normally go
55 deg c
66 deg c
75 deg c
78 deg c, for no other reason but i like to do it that way and it works for me, if im 1 deg short or upto 2 deg c over ill just leave it, apart from that ill run some wort through the heat exchange until the temp comes up.


Now for the fast way, i do this in Hefe and lighter colored beer, I do everything upto the boiling proces, but now i put the lid on the pressure cooker, once it comes to full pressure i turn the heat off and let it come down to under 100 deg c by its self, the i add it back to the mash, what happens here is the grain will not boil but the grain will get over boiling point, i get the same benefit with out changing the color to much, maybe 1-2 SRM rather than 5-6.... Its as easy as that



What i would recommend, for anyone, on any system is this, Do a single infusion mash at what ever temp you have done before, when your done with the sacc rest, take out as much of the grain as you can upto about 30-40%, put it on the stove and bring it to a boil, keep stirring and let it boil for 5-10 mins, add it back to the mash tun, do it again if you get under 74 deg c, if you get over that just do it once, then see the difference in the final beer.......if that was not so hard do another beer, a standard APA and do a initial rest at 55 deg c, then do a decoction stopping at Sacc temps for 10 mins, then boil, add it back to the mash, after mash is complete take more out and bring it straight to boil........add it back, there you have done a double decoction, It is that easy, from there try a tripple......

if you dont notice a taste differance you will see a huge jump in mash effeciancy, and a cleaner tasting beer


Try it

Enjoy
Thank God All Mighty For Titties and Beer
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Ozbrewer
 
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Mon Oct 23, 2006 4:26 am

This was a great show, but I still would pay $$ for a video of someone doing a full tripple decoction mash. Maybe we could have a TBN "13 hour boil" episode or another collaboration between Krotch and Oz. Krotch's brewing video came out nice last time. I have done 2 decoction mashes with, shall we say, less than desireable outcomes.

Put it up for a vote..
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Gucci Pilot
 
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Mon Oct 23, 2006 4:48 am

thanks for that oz. keeps it simple and worth having a go. (and centigrade temps wahey) :D
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brewsters millionths
 
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Mon Oct 23, 2006 8:23 am

Oz,

Thanks for starting that subject or opening Pandorra's box for that matter ;)

There are 3 main procedures that faszinate me the most in brewing: mashing procedure, lager fermentation procedure and drinking the finished beer ;). Decoction mashing is a big part of the mashing procedure for me and more than half the beers I brew use deoction mashing. When using a non-heated mash tun (e.g cooler) this is the most practical way of stepping the mash. And since 75% of the beers I brew are Bavarian Style, a decoction mash never seems out of place for them. Even my first AG batch (a Doppelbock that I actually augmented with DME to get to the desired OG) was a double decoction, after I did a partial mash double decoction for an Oktoberfest. Speaking about spinning your wheels ;).

Recently I started reading more German based brewing literature which enriched my knowledge about deoction mashing quite a bit.

But there seem to be a few misconceptions about conducting a decotion mash out there which I would like to discuss. I would have liked to call in for this, but my Sunday nights are way to busy to listen to the BN.

Tannin extraction: Boiling of the mash actually does extract tannins and other less noble compounds from the grains. This is part of the deoction flavor. But due to the low PH and high concentration this extraction is less than what it would be at higher PH and lower wort concentration.

Thickness of the mash: The decoction should be pulled from the tick part of the mash, but not that you end up with only grain in the mash kettle. If I use a strainer to pull the grain, I always add some more of the liquid mash to keep the deoction mash manageble. Having to much grain and to little liquid calls for scorching and will impeede the enzymatic activity that you actually need to convert the decoction before getting it to a boil. Narziss (Greman brewing guru) mentions a decoction thickness of about 2 L/Kg (~1qt/lb) while the initial mash thickness was at 4 L/Kg (~2qt/lb). Sure, you won't brew a doppelbock with a 1:4 mash sice that would create way to much run-off for the extract that you need from the grains. But that shows that the decoctions should not be as thick as oatmeal. I also add about 10-15% water to the decoction to compensate for the boil-off.

Boiling: When I heat my deoctions, I aim for a 1-2C (2-4F) rise per min. This means that it takes longer to bring the deoction to a boil, but it will be gentler and I only have to stir a little every 2-3 min. I even use a cheap enamel pot for heating/boiling the mash and was raking the leaves while doing the decoction mashing. If I get close to the conversion rest I would stir more often to have a more even temp distribution for the rest. I only burn the mash if I try to rush it.

Enzymatic activity: The enzymes will get hurt during deoction masing. But it is true that most of them are in the liquid part. According to Narziss, a tripple decoction can result in an up to 90% enzymatic power loss at the end of the 3rd decoction. Though the enzymes are hurt considerably, making the starches more accessible helps them. Because of the conversion of earlier decoctions, the beta amylase will also have much more starch ends to work on during the conversion rest.


As Oz said,
The best way to enter deoction mashing is with a single decoction to mash-out. At this point your mash is converted and you don't have to worry about a conversion rest for the deoction. Just pull a tick part (not to thick though) and bring it to a boil. This should take about 15-20 min and boil it for another 5-15 min before returning it to the mash. This is also the deoction that Dan Gordan uses for his Maerzen.

Kai
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Kaiser
 
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Mon Oct 23, 2006 11:54 am

FWIW, in a blind taste test of infused beers and the exact same recipe brewed as a single decoction with a 30-60 min. boil, 52% 42 tasters found no difference or preferred the infused beer to the decocted one.
Denny
 
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Mon Oct 23, 2006 12:45 pm

Denny wrote:FWIW, in a blind taste test of infused beers and the exact same recipe brewed as a single decoction with a 30-60 min. boil, 52% 42 tasters found no difference or preferred the infused beer to the decocted one.


I'm really interested in the details to this test, since it is hard for me to believe that a 60min boil didn't leave any noticible taste difference. Is there any on-line version available. When I searched for it, I only found an old forum post calling for participants.

I attempted such an experiment myself, but the brewing of the single infused and double decoctied Oktoberfest for that experiment got split apart by a rather long time (2 wks). While I recently served the single infused beer at a party, the double decocted beer is still lagering.

I did however find, that the single infused beer did daste less malty than I remember this recipe to taste when it is brewed with a double decoction. But since so many other things can be different, I will have to try this experiment again when I can actually brew 2 beers the same day.

Kai
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Kaiser
 
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Tue Oct 24, 2006 7:53 am

The results aren't available at this point, because I've taken so much crap when I alluded to them that I decided I didn't have the energy to go through with it. I think I'm going to see if I can enlist some help and maybe get it written up sometime this winter.
Denny
 
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Tue Oct 24, 2006 8:06 am

Denny wrote:The results aren't available at this point, because I've taken so much crap when I alluded to them that I decided I didn't have the energy to go through with it. I think I'm going to see if I can enlist some help and maybe get it written up sometime this winter.


That's what true pioneers do Denny, they take crap. Columbus, the Wright Bros., Elvis, heck the person who invented the wheel probably got killed and eaten before the rest of the tribe figured out it wasn't evil (or was it??).

Keep it up if you can bear the crap 'cause people like you help the rest of us every day.

Thanks for the effort. I KNOW it is appreciated!

Rob
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Speyedr
 
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