Decoction Mashing on efficiency

[99blackgt]

When doing a Decoction mash. Does it hurt your efficiency or help it? I saw someone post something about it helping their efficiency, but i would assume it would hurt it. This is because i assume that when you boil the wort, you kill whatever enzymes are in that portion of the wort.

I know you don't boil the entire wort, but still... Wouldn't that hurt your efficiency, or make your mash take longer to completely convert all the starches?

Fill me in, i did search and read a bit, but this doesn't seem to be covered

 

[GilaMinumBeer]

I have read the opposite. While heating the decoction does denature the enzymes in that pull it also bursts open the starches in that portion of grain making them more available to the enzymes left in the kettle.

I have always understood that decoction improves efficiency in addition to generating melanoidins.

 

[cubbies]

I get my best efficiencies with decoction mashing. Of course I am only one brewer and I decoct once MAYBE twice a year, so take it with a grain of salt. I get noticeable increase though.

 

[AnonyBrew]

I don't know all the scientific details behind it, but when I've done decoctions my efficiency is much higher than regular step mashing.

So my vote is decoction mashing = higher mash efficiency.

 

[bradsul]

Kaiser put some excellent articles on the wiki and in his videos that will probably resolve most of your questions. They are well worth the time to read and watch.

From my own experience, when you pull your decoctions they are very thick and the enzymes almost entirely remain in the liquid in the mash tun. The few enzymes that are brought into the kettle are used in the mini-rest on your way up to boiling to convert the starches that are available in the kettle. So while you are destroying them in terms of the main mash, you are still making full use of them.

When you decoction mash you are both breaking down further starches and exposing them to the enzymes even more often, which definitely helps with maximizing your extraction.

 

[BigEd]

When doing a Decoction mash. Does it hurt your efficiency or help it? I saw someone post something about it helping their efficiency, but i would assume it would hurt it. This is because i assume that when you boil the wort, you kill whatever enzymes are in that portion of the wort.

You aren't boiling the wort you are boiling the wet grains. Most of the liquid is drained off before adding the grain to the boiling vessel. bradsul has covered things in that some enzymes will be denatured since some liquid will be included. However, the heat and mechanical action of the boiling breaks down the particles of malt as well as the particles of starch within them. This allows the starches to be more easily accessible to the actions of the enzymes. Also in a traditional decoction the removed grains would be subjected to a rest at sacchrification temps before they are brought to a boil. A decoction isn't going to dramatically change your conversion efficiency but it will usually add a couple of points to your norm.

 

[menschmaschine]

While heating the decoction does denature the enzymes in that pull it also bursts open the starches in that portion of grain making them more available to the enzymes left in the kettle.

+1. This is what Noonan says. However, since at least one decoction is typically done to bring the mash to a dextrin rest, much of the starches coming from the decoction are converted by alpha amylase enzymes, resulting in a more dextrinous wort.

So, higher efficiency... yes, but it's usually in dextrins vs. fermentable sugars.

 

[Yooper]

One thing I do (maybe because of a post I read from the Kaiser) is to bring the decoction to the saccrification rest and keep it there before raising it up to a boil. Unless it's a mash out decoction, of course!

 

[Malticulous]

I think a acid rest helps by suspending the enzymes. Pulling thick mash and resting at 160 in the decotion helps too. The rest at 160 breaks it up fast, and later it gets broke down to more fermentable sugars with the lower temp rest in the main mash where most of the enzymes still are.

 

[99blackgt]

i was just going to do a double decoction, protein rest, boil, sacchrification rest, boil, sparage

Do you take grains off the top and add them to boiling water? I was under the assumption you drained wort from the bottom and boiled that?

i wanted to try this, because i'm going to do a very lite ale in my new mash setup i just finished (posting about that later probably) and i wanted to make sure it had a good malty taste to it.

 

[menschmaschine]

i was just going to do a double decoction, protein rest, boil, sacchrification rest, boil, sparage

What temps for the protein rest and sacch. rest?

 

[Yooper]

i was just going to do a double decoction, protein rest, boil, sacchrification rest, boil, sparage

Do you take grains off the top and add them to boiling water? I was under the assumption you drained wort from the bottom and boiled that?

i wanted to try this, because i'm going to do a very lite ale in my new mash setup i just finished (posting about that later probably) and i wanted to make sure it had a good malty taste to it.

no, you don't boil the grains in water! You pull the grains out of the mash tun and bring them to a boil. Like I said, I stop at a saccrification rest temp first, the bring to a boil. Then add back to my MLT to hit the second temperature rest.

 

[Yooper]

Some links to better explain:
Decoction mash - Home Brewing Wiki

and my favorite:
https://www.homebrewtalk.com/f36/decoction-mash-video-59872/

 

[Malticulous]

Until mash out use thick mash (mostly grain.) For mash out go ahead and use all liquid.

 

[99blackgt]

ic.. I usually do my initial rest at 127* (ish) and I usually only do that if i'm using adjucts (i have 50lb of cracked corn i use for maze that i crush and throw in certain things) then sac at 153-155*, sparage 170*

So you're saying you do the rest at 12X* or whatever. Get a ladle or similar and pull out 2 gallons (or whatever you calculate) worth of wort/grain, get it up to 155* for 10-15 min, then boil that. Dump it in to get desired sac temp (bit by bit, measuring along the way), let that rest for 45-60 or w/e the iodine tells you to do. Then take X amount of wort out of the bottom, boil it to get up to 170*, and then dump it all, sparage like usual?

Makes a little more sense. I'll read those links you posted. Again, i'm sorry for being a noob. I'm trying to ask more questions now instead of trashing batches of beer. I've been reading the wiki's but it's a lot to take in all at one time, while still studying all my history / stat work for skewl. I'm on my way to bdubs now, but when i get home i'll give the decoction section of the wiki another read. I had read the stages before, but it didn't mention any positive OR negative effects on efficiency, so i wanted to check.

Thanks guys

 

[Jack]

I find that it helps efficiency.

Before boiling grains, you allow >20 minutes at a saccharification rest temperature so you are still getting conversion of those grains.

 

[Kaiser]

+1 to higher efficiency. But this has been covered already.

but it's usually in dextrins vs. fermentable sugars.

This actually depends on how you run your decoctions. I have made decoctions with the purpose of creating a more fermerntable wort than with a non decoction mash. While the decoction itself will be rich in dextrins, these dextrines will be attached by the b-amylase in the sacc rest. How much attack happens depends on he temp and time of that rest.

Kai

 

[SpanishCastleAle]

This actually depends on how you run your decoctions. I have made decoctions with the purpose of creating a more fermerntable wort than with a non decoction mash. While the decoction itself will be rich in dextrins, these dextrines will be attached by the b-amylase in the sacc rest. How much attack happens depends on he temp and time of that rest.

Daniels in DGB said that the Vienna/Oktoberfest/Marzen beers were often decoctions and the sacc rest was usually ~149o F so now that makes more sense. When I did my Vienna I didn't get any more efficiency (maybe a point) and still don't know how fermentable it was (fermenting 12 days now...racking this weekend).

One thing I didn't really understand was why the bigger Oktoberfest beers had longer decoction boil times than the lower OG Viennas? Purely for deeper flavor? I went ~35 minutes and it smelled awesome at the end.

 

[illin8]

no, you don't boil the grains in water! You pull the grains out of the mash tun and bring them to a boil. Like I said, I stop at a saccrification rest temp first, the bring to a boil. Then add back to my MLT to hit the second temperature rest.

One thing I'm having trouble with is won't boiling the grain only (minimal wort content) have the propensity to 'scorch' the grains? I've never done one and am trying to understand how it won't scorch...

 

[bradsul]

One thing I'm having trouble with is won't boiling the grain only (minimal wort content) have the propensity to 'scorch' the grains? I've never done one and am trying to understand how it won't scorch...

While your decoction pull is very thick it isn't entirely grain. Sometimes I even add a little extra water if I know I'm going to be boiling for an extended period. You do need to pull some mash liquid with it. Yes it will definitely scorch if you don't stir (which you will be doing a lot of ). But once it actually gets to boiling I find it's not necessary to stir much, it's just during the heating phases.

 

[menschmaschine]

*Raises hand*

I've scorched. Beer tastes like... well hard to describe, but it's not good... barely drinkable. It was a year and a half ago and I still have one case left (out of 4), hoping the flavor would diminish. No luck.

It was my first decoction and it was an Altbier. Lesson learned?... stir a lot!

 

[SpanishCastleAle]

FWIW, when I did my Vienna mash I pulled the thickest decoction I could. I would fill a quart measuring cup to the rim and let it settle for a moment and then decant as much liquid off as possible and keep the thick mash for the decoction. But then I infused the decoction with hot water to get it up to conversion temp quickly. It wasn't too much water and I measured the pH of the decoction and it was just slightly higher than the mash but still below 5.5.

I put the decoction in a SS pot just because I was afraid an Aluminum pot might scorch it. I just didn't crank the heat too much and stirred occasionally and there was no scorch on the pot (nor any burnt smell). But the end of the decoction boil really smelled awesome and was noticably darker and was quite thick at that point too. The awesome aromas didn't really develop for a good 15-20 minutes of boiling but that may have had to do with the thickening of the decoction as it boiled.

EDIT: The above was to raise it to sacc rest...I used a thin-mash decoction (almost pure liquid) for mash out and didn't boil it as long...just enough to get a hot break.

 

[Kaiser]

I just didn't crank the heat too much and stirred occasionally and there was no scorch on the pot (nor any burnt smell).

This is key, heat the decoction gently. I even keep the lid on which takes even less heat to keep it boiling. Don’t worry about trapping DMS. This will be boiled off later anyway.

Don’t try to make the decoction too thick. 1-1.25 qt/lb are what you are looking for. Basically the thickness of the grains when they settle on the bottom. That’s where the decoction is pumped from after the agitator has been stopped and the grain settled.

Kai

 

[SpanishCastleAle]

Kaiser,
I hadn't read your decoction page when I did my Vienna but I noticed this:

All the decoction schedules provided here assume a decoction rise temp of 2-4 *F/min (1-2 *C/min).

I used a small infusion to raise the thick decoction up to sacc rest temp more quickly...was this undesirable? What is the reason for the temp increase rate...just to prevent scorching or other reasons?

 

[Kaiser]

What is the reason for the temp increase rate...just to prevent scorching or other reasons?

Yes its just to prevent scorching and give some guideline on how fast a decoction should be heated. If you can heat faster w/o scorching go for it.

Kai

 

[babalu87]

I do mine in a heavy pot with a round cast iron heat diffuser pad on my stove-top burner

Works like a charm and no scorching

 

[SpanishCastleAle]

FWIW, I racked my Vienna this past Sunday and the gravity was a little lower than I expected. OG was 1.053 and the gravity is 1.013 right now. That's 15 days after brewing it and I pitched cool (I pitched at ~60o F and then immediately put it in a 52o F fridge). This was with White Labs Oktoberfest/Marzen (65%-73% AA) yeast in a 1 qt. starter.

I can't say that it was due to the decoction though. My sacc rest was 149o F...I just used some averaged numbers from the DGB book for temps/times.

 

[balto charlie]

I just did my first double decoction brew yesterday thanks to Kai's you tube video. Brewed Bradsul Vienna. My efficiency went from 73% to 84%:rockin: I hovered over the pot stirring constantly while ramping up the heat to reach boil quickly. No burn, no scorching and increased efficiency. Wonderful smell. Overall the process was a bit tedious but with a little practice should become routine. I plan to use this method for most(if not all) of my lagers I brew this winter. I have 3 more in the planning stages. Might even try a triple. Charlie
PS Also I didn't pull out the thickest part of the mash to decoc but removed the thinnest part (top liquid) and put that into a preheated cooler. I then boiled all of the grains and liquid left in the pot.

 

[humann_brewing]

It is still early, my first decoction is half way through its boil, but I going from the pre-boil gravity, I think I might hit 90% on the brew today, my first lager.

 

[humann_brewing]

Well, my first decoction I did took forever and makes you sure appreciate the simplicity of a single infusion. I don't see myself doing this method very often. I think I was over 6 maybe even 7 hours on this brew.

The good side is I think it helped a couple of percentage points on the efficiency I was at 87% brewhouse efficiency on this brew. At the end I had 5.5 Gallons, maybe a little more of 1.044 wort using 7.75 LBs of grain.

 

[SpanishCastleAle]

Mine take some extra time too. I obv don't homebrew to save time...but there is a practical limit for everybody.

One thing I do to try and save a little time is to do combination infusion/decoction. I'll dough-in to hit the acid rest temp of 95o F (really thick mash...like .8 qt/lb)...then infuse to hit the protien rest temp of 122o F (about an average mash now...maybe 1.25-1.33 qt/lb)...then immediately pull an uber-thick decoction (6 qt.) but then I'll infuse the decoction with 2.5 qt. boiling water to get it up to a high sacc rest as quickly as possible and I only rest it there for about 10 minutes before I add heat and start building up to the boil. When it's all back together it's about a 1.5 qt/lb mash accounting for boil losses (which are significant). I'm still tweeking it but I'm very close to having it dialed in.

But between that and long boil times (because I'm using Pils malt) it ends up being a 6-7 hour ordeal. Just between the rests (20+60 min.), the decoction rest/boil (50 min.), the sparge (30 min.), the full boil (100 min.), and chilling (40 min.)...that's almost 5 hours there and that's not including any heating times/etc.