Decoction - quick queries

[Adr_0]

I've just moved up to Gladstone and only have half of my brew stuff and will be building a 20-23L 2V + bucket AdRIMS system. Note that AdRIMS is basically just recirculation of the mash with a pump, and no direct heating to the recirc line.

As I work through some examples, it's clear that I'm a bit light on with the mash tun volume, and would have a lot more flexibility if I draw off some liquor towards the end of sacch, boil, then add back to achieve mash out. This leaves a bit more room for sparging as well.

I actually thought this was a single decoction, but as I do more reading it is clear that it is only psuedo-decoction: you need to take off grains as well as liquor, though to be honest I don't really see the point with the Sacch->Mash Out step.

Anyway, for when I do wheats, pilseners, O'fests I will probably do at least one genuine decoction draw-off.

So a couple of queries:
1) Say in a 30L mash, you need to draw off 10L of liquor, rest, boil, add back to mash. How much grain should be in this? What is considered 'stiff' for decoction purposes? For multi-step infusions I mash in (protein) at 1.6-1.8L/kg but this wouldn't be practical for decoction. So something in the 2-2.5L/kg range?

2) Further to the question above, if it were just liquor or very thin, I imagine there would be potentially more harm than good as it would just denature enzymes without breaking down starch/husk cell walls?
I think to answer this (with practicalfool's input) I guess that if the decoction only has a small amount of grain you will both denature enzymes and increase pH/tannin extraction = bad.

3) Any good online links for the starch mechanisms? I'm pretty comfortable with the basics but not sure what goes on with the starch/husk breakdown stuff when you rest and boil.

4) Is it a requirement to add the boiled grains back to the mash? Is this particularly critical adding from Protein-> Sacch (i.e. have the grains in the mash for sacch) or should they just be returned to the mash for mash out/sparging?

Thanks,

Adro

Edits in italics

 

[pk.sax]

I only feel confident commenting on 2 points:

1. Grains in a thick decoction cause a drop in ph which stops tannins from the husks leaching. A thin decoction might hurt.

2. Grain, being solid, has a higher thermal mass and you would need smaller amounts of a thick decoction to attain your target temps than if you only did liquor.

 

[TheBeerKitchen]

With the thick mash, it has to be as thick as possible with enough liquor to not scorch the grain. Remember to keep it moving as well.

Regarding a Mash Out decoction, what does it matter if you Denature enzymes in the final rise? Thats the point of mash out.

Also for total liquor to grist, i would go thinner, say 3L/1Kg. You leave most of the liquor behind, resulting in good enzymatic activity for the rest, and then add it back. Once you are at temp, you pull the next decoction, so your mash is resting at the next temp for the time you boil the decoction, then you add it back, and once you are at temp. If you dont, you will end up spending 10 hours brewing. It is possible to not add it all back. For instance, you can pull a massive decoction for acid rest-sacch rest, but add enough back to get to protein, then keep boiling the remainder of the decoction. This way you dont have a huge protein rest, then you add the rest back to get it up to sacch.

You can then go on and do mash out once you are fully converted.

Keep in mind to add decoctions back gently, as you can get an almond like flavour (benzaldehyde).

I would mash in at protein rest, and not bother with the acid rest, just get some Acidulated malt and work with your water to acheive the ideal PH. This way you do a protein rest, a B sacch, an A sacch and Mash Out. Although, i wouldnt bother with the long protein rest for most beers either, unless there is higher amounts of Wheat or Rye.

If you have any of the decoction left after you hit your temp, let it cool to the rest temp for the main mash before adding it back, this way you dont overshoot, and you know how much decoction you are pulling for the next decoction.

It is a great process, and allows you to be more hands on, especially with the HERMS and RIMS setups that are completely automated these days. I would rather do a decoction and get some good colour and flavour than add melanoidin malt and step it automatically.

 

[Adr_0]

Yeah, sounds good. The rig I'm building at the moment is geared towards ease of use and effectiveness.

No dramas with the Sacch-> Mash Out decoction. My only question here would be do you bring grain across for that one too? Is there any point? I guess if you don't it's not really a decoction.

At the moment I will just do a single decoction thingy (just with liquor from Sacch->Mash Out) and then probably try and use a stainless mesh screen + BIAB bag, trying to minimise any area for liquor to be out of contact with the grain. Food for thought.

Thanks for the replies guys.

 

[menoetes]

Adr_0, the host gets quite technical and has quite a different system to me, maybe you can make more sense of it.

I think I got the general jist of it though and tried to copy him in my own way. This guys does the boil almost completely with the grains and explains the tannins thing. Apparently as you boil the grains they release more fluid and I'd agree with that, mine became something like a rough grainy porridge. It's rough on the ol' stirring arm though, especially if you're just doing it on a stove top with a large wooden spoon

I hope it is of some help.

 

[Adr_0]

Geez, that video is hardcore. I'm always paranoid about drinking on a brewday and couldn't even begin to contemplate doing it for all that. Awesome vid though.

...and answers most of my questions. Still not sure what the last Sacch->Mash Out step is called if it's just liquor and no grains. I guess it does need grains to be called a decoction?

It seems that a triple decoction is traditionally:
Acid -> Protein
Protein -> Sacch
Sacch -> Mash Out

The Sacch->Mash Out obviously doesn't have a rest and goes straight to boil, but does it have grains or not and is there any advantage to adding grains?

 

[Ducatiboy stu]

You dont need the mash out step. Just go sach --> kettle.

 

[TheBeerKitchen]

You dont need the mash out step. Just go sach --> kettle.

Mash out is needed in my opinion and is beneficial and is used widely for a reason. It slows the enzymes working while you sparge. Fly or Batch, you still take time, that contributes to the conversion, what if you got stuck halfway through lautering first runnings?. If you raise the entire mash to 78, you slow the enzymes (not immediately stop) and get a more consistent result. If not, you cannot accurately make adjustments next time. It also allows more sugar to go into solution, allowing better efficiency and a better sparge.

As for the question about if its still a decoction. Of course it is, Decoct simply means to boil down, or to extract from boiling. Its still part of the mash, you just take the thin part. In a traditional brewery, the lautering is not completed in the mash tun, and the mash is taken into another vessel designed to seperate the liquid from the grain. When you take the liquid, you will get some grains.. Just dont take meaty scoops of grain with a little liquid.

Thick mash = grains with some liquor to stop it scorching
Thin mash = liquor with a little grain, it doesnt have to be clean, clear first runnings. Just the more liquid part of the mash. The bit that has settled above the grain bed.

I decoct, and once i'm at mash out temp, i start the vorlauf and then lauter into the kettle. while lautering, you can either fly sparge, or wait and batch sparge. Either way, you give it a small rest while you vorlauf and get good clarity.

Hope it makes a bit more sense!

 

[Ducatiboy stu]

Mash out is needed in my opinion and is beneficial and is used widely for a reason. It slows the enzymes working while you sparge. Fly or Batch, you still take time, that contributes to the conversion, what if you got stuck halfway through lautering first runnings?. If you raise the entire mash to 78, you slow the enzymes (not immediately stop) and get a more consistent result. If not, you cannot accurately make adjustments next time. It also allows more sugar to go into solution, allowing better efficiency and a better sparge.
!

Most of the conversion is done in the first 20mins. So if you do a 1hr mash it pretty much fully converted so there is nothing left for the enzymes to do. So a mashout step is pointless.

 

[manticle]

While mash out is not needed any more than decoction or step mashing is needed, you can get different results by doing so.
What does conversion entail? Long chain starch gets converted to shorter chain sugar. How many different sugars are there? How many enzymes doing the conversion?
I go to great effort to tweak my mash profile very specifically so why wouldn't I want to do a 10 minute rest to fix that profile? Beta can cut further what alpha has already had a go at so mash out stops that.

 

[Ducatiboy stu]

Batch sparge with boiling water. Solves to issues of stuck sparges and fluidity. Makes batch sparging much easier.

 

[manticle]

I'd have concerns sparging with water that hot. Nonetheless, I sparge with water at about 74 and don't get set mashes, etc. I also incorporate a 72 deg c rest so bumping up to 78 is very simple before runoff.

 

[TheBeerKitchen]

Conversion continues past "starch negative". Not all conversion is done in the first 20 minutes and not all "Starch Negative" results are within 20 minutes.

As stated, it is not necessary to brew beer, but there are benefits to doing it. Just like the benefits in decoction mashing. A MO decoction will help with efficiency if nothing else, why omit that from the day, when it only takes a few minutes? Especially if you are doing a super long mash anyway.

I always do it, regardless of the type of mash, decoction, infusing, or step. I usually seperate my alpha and beta rests, sometimes my beta rest is short, and the alpha rest quite long, it depends on the final result i want.

As for boiling sparge water. I sparge with 78 degree water. I'd also like to know the temp of the grain bed after sparging with water that hot. It would be interesting to know how variable it is dependant on the volumes. Obviously with a higher L:G ratio you have less sparge water.

 

[Ducatiboy stu]

And what would those concerns be. Because tannin extraction is not one of them.

 

[manticle]

Tannin extraction is exactly one of them, especially since my grain bed is 72. Have sparged with 80+ water before and been unhappy with the results so I switched to cool sparge. Same efficiency, no stuck mash, better flavour. Even if tannin extraction is not an issue, I can't see an advantage to heating sparge water hotter and longer over a mash out step and cooler sparge. We're possibly talking minutes saved or lost on brewday.

 

[Ducatiboy stu]

Well I sparge with boiling waterinto my mash tun @64-68*c. I dont see the point of raising to 72*, resting etc. But then again I dont do Lager styles.

Even after the 3rd sparge the bed does not reach the temp to get tannin extraction. You would be suprised just how little it does actually raise the temp of the grain bed.

Just because its unconventional does not make it wrong or bad.

Dont knock it till you try it. You might get a suprise.

 

[manticle]

72 is a glycoprotein rest and has a significant effect on head retention.
Not knocking what you do if it works for you but as mentioned I have tried hotter sparges and was unhappy with the results.

 

[Ducatiboy stu]

I have never had any head retention problems. Except for dirty glasses.

And never had any tannin issues either.

 

[TheWiggman]

Curiously, are you aiming to achieve a certain flavour profile from the decoction or is it more a matter of your system limitations? I was under the impression that decoction adds a character to the beer to suit certain styles. Thus if doing a decoction, why not just target the one step and use the AdRIMS to do the other steps through infusion?
Or if it's to venture new grounds, carry on...

 

[manticle]

You misunderstood my position Stu. I didn't suggest a 72 rest was necessary for head retention - just that it has a significant effect on it.