Biab Hochkurz And A Single Decoction

[iralosavic]

G'day,

I'm planning to make a Euro lager (German Pilsner if you will) on Sunday and am trying to plan my mash schedule ahead of time.

I want to give the Melanoiden malt a miss and attempt to replace (even improve upon) it by introducing a decoction to my mash.

After reading around, I've decided I want to give a Hochkurz style mash arrangement a go, as from what I have read I feel this should result in the best balance with the least compromise. The issue I am having is deciding where to place the decoction. If I can, I'd rather avoid the need to hold the decoction at a beta amalyse rest on the way to the boil, as my decocting equipment (18L aluminium pot on a gutless stove) lacks a lot of control/accuracy and I can forsee myself becoming overwhelmed on a first attempt. I also have the issue of being a full volume BIAB masher, so the 1/3 volume law limits me to larger temperature jumps.

Details:

Recipe for 21L @ 1.048 (using 75% efficiency in BM until I fine tune my actual results)

88% Pilsner
10% Munich I
2% Acidulated Malt (only using the minimum calcium chloride addition to achieve target calcium)

Halertau Mittlefrueh to 28IBU @ 40. (BM changes this to 33IBU when no chill is ticked. I think either result will still suit the style and my pallate)


Strike water: 29.5L.
Total Mash Volume: 33.8L

Dough-In @ 55c
Protein rest @ 55c for 10 minutes
Beta Amalyse rest @ 63 for 10 minutes
Alpha Amalyse rest @ 68 for 50 minutes
Glycoprotein rest @ 71 for 10 minutes
Mash-out @ 78


According to respected forum members, 1/3 of the total mash volume should be ideally be removed (11L). Using the following formula, I can therefore conclude that the only step with a big enough jump to require such a volume is the 8c step from 55c to 63c (11.2L), however this step would require a saccharfication rest while bringing the decoction to the boil. Mash-out would be the next best option (~9L), but it would need to be a thick mix in order to release the melanoidens, which seems to go against standard brewing practice.


Decocton Volume = Total Mash Volume x (target temperature - starting temperature) / (boil temperature - start temperature)


Anyhow, before I get too far ahead of myself, can anyone please help me out? Cheers

 

[Nick JD]

Sounds like you have it sorted. My advice would be to not get too down on yourself if you miss target temps the first time round. While that equation is pretty good - what it fails to account for is temp loss in the mash during decoct and the "pissing about" factor.

As a general rule with decoctions, if you take slightly more than the equation says, and add back into the main mash incrementally until your target temp is reached ... the stuff left over can be added later when it's cooled a bit.

Worst thing is when you've added all the decoction back and it's not come up to the correct temp. Pulling more than the equation says fixes this.

Second time round all your notes will indicate how to get it perfect.

 

[iralosavic]

Thanks for the tips, Nick. So you think I should just decoct the 11L and use it to jump from 55c to 63c?

This does introduce more questions though:

Do I remove the decoction after the protein rest?
What do I do with the mash while my gutless stove slowly does it's thing?
At what temperature and for how long do I hold the decoction at a saccharification rest?

I think if I am happy those questions are answered I should be 'right.

Edit: I guess Im worried about boiling 1/3 of my grain and denaturing the enzymes before Ive maximized the starch conversion. 1/3 is a lot. However, if I hold the decoction for a while, the main mash could be in protein rest limbo for an hour!

 

[manticle]

G'day,

I'm planning to make a Euro lager (German Pilsner if you will) on Sunday and am trying to plan my mash schedule ahead of time.

I want to give the Melanoiden malt a miss and attempt to replace (even improve upon) it by introducing a decoction to my mash.

After reading around, I've decided I want to give a Hochkurz style mash arrangement a go, as from what I have read I feel this should result in the best balance with the least compromise. The issue I am having is deciding where to place the decoction. If I can, I'd rather avoid the need to hold the decoction at a beta amalyse rest on the way to the boil, as my decocting equipment (18L aluminium pot on a gutless stove) lacks a lot of control/accuracy and I can forsee myself becoming overwhelmed on a first attempt. I also have the issue of being a full volume BIAB masher, so the 1/3 volume law limits me to larger temperature jumps.

Details:

Recipe for 21L @ 1.048 (using 75% efficiency in BM until I fine tune my actual results)

88% Pilsner
10% Munich I
2% Acidulated Malt (only using the minimum calcium chloride addition to achieve target calcium)

Halertau Mittlefrueh to 28IBU @ 40. (BM changes this to 33IBU when no chill is ticked. I think either result will still suit the style and my pallate)


Strike water: 29.5L.
Total Mash Volume: 33.8L

Dough-In @ 55c
Protein rest @ 55c for 10 minutes
Beta Amalyse rest @ 63 for 10 minutes
Alpha Amalyse rest @ 68 for 50 minutes
Glycoprotein rest @ 71 for 10 minutes
Mash-out @ 78


According to respected forum members, 1/3 of the total mash volume should be ideally be removed (11L). Using the following formula, I can therefore conclude that the only step with a big enough jump to require such a volume is the 8c step from 55c to 63c (11.2L), however this step would require a saccharfication rest while bringing the decoction to the boil. Mash-out would be the next best option (~9L), but it would need to be a thick mix in order to release the melanoidens, which seems to go against standard brewing practice.


Decocton Volume = Total Mash Volume x (target temperature - starting temperature) / (boil temperature - start temperature)


Anyhow, before I get too far ahead of myself, can anyone please help me out? Cheers

I often use a fairly similar regime.

First of all, I think Nick is right about not stressing. If you pull more decoction than you need, as long as it's had some time at the sacch conversion stage, you will be fine.

What I do in these situations is pull the decoction after I've rested at 63 and raised to 68 (but before the 68 rest actually starts). My high sacch rest will go for 40-50 minutes at least so plenty of time for a good boil. If only doing a single, I'll usually add back to the mashout so there's an extra 15-20 minutes of decoction boil time for those flavours to develop. I may sometimes pull an extra one and boil both side by side - the second with more liquid and boiled for less time (in which case the first gets pulled a bit earlier).

If you rest it in your tun at 63 for 10 minutes, a lot of conversion will take place. Raise the heat slowly at first and the temp ramp will ensure more conversion and a touch of dextrin. If you raise it to 68 in the tun, even some of that is taken care of for you.

I do have the ability to raise temp if I don't hit them exactly so step mashing and decocting are stress free for me in that regard but if you can manage the steps you have suggested, decocting won't add in too much more bother.

If the above doesn't make sense, feel free to ask - this is a common schedule for me and I'm happy to clarify what I do. The results make sense in terms of my reading but mostly in terms of my perceived results.

 

[dr K]

I feel that you should perhaps first get an understanding about what decoction is and why it works (as it seems to some counter-intuitive).
You should also do some research into mash thickness and enzyme denaturation.
A thick mash protects the enzymes, a single step infusion is ideal for a 67-68C mash with highly modified (read every malt you can but just about). The thick mash (say 2.2 to 2.5:1) protects the Beta Amalyse whilst the Alpha is happy at 67-68, you get a balanced (enzyme-wise) beer that you can happily sparge in-situ. If you were to use a seperate lauter tun then you would require a thinner mash cuse 2.5:1 is too thick to effectivley move esp after conversion, so you start a bit lower with a higher ratio , say 3.5 to 4.0 do a beta rest (funny expression) at maybe 63 then work up to alpha's happy zone.
I am not for a moment saying BIAB of itself produces bad beer (bad brewers produce bad beer) but at the 7:1 or higher full volume ratios you are already decimating (at least) your enzymes. Take 1/3 out, you mention 11 litres so I guess you mean the already enzyme depleted liqour as well as the grain then you heading for tears before bedtime.
When you decoct you take mainly wet grain out and leave the enzyme rich (or deplteted) liquor behind because as you boil the decoct (and you have to boil well not just hit and close) you will destroy any AB enzymes in the decoct. This is why a decoction normally starts with a thicker mash.
I hope that this is of assistance.

K

 

[dr K]

O
and on another, although historical point perhaps.
Decoction brewing arose before we had thermometer and before we properly understood malting (let alone what yeast was)
The mash water was heated till it was "right" probably not long after bubbles appeared (do it and check the temp)
The grain was added and of course the temp dropped (the lower the L:G the greater the drop) so you mash in at say 55 if you went 2.2:1, or whatever.
Removing about a third, boiling it chucking it back into the uninsulated mash tun might see you hit 60.
Do it agian and you might get say 65
And again 70..
sound familiar?
Its not magic, its a combination of history and science.

K

 

[iralosavic]

Thanks for your help, Manticle. And thanks Dr for looking around my question and giving me more to think about.

I might skip the decoction on this occasion, but follow through with the rest of the schedule using an infusion to step up from 55 to 63.

I was planning on using a basic water mixing calculator to determine how much hot liquor will be needed, but I'm not sure whether I should be using the total mash volume including grain to make the calculation or only the strike water?

Or is there an easier way to calculate this?

Cheers

 

[NickB]

Your other option might be to do a thin decoction (liquid only) and bring up to the boil for however long you desire, then add back to achieve mash out temps. Will give you some decocted flavour, while not making you stress about scorching grain etc. Once you get a feel for the amounts used in this scenario, then aim for a 'proper' decoction down the track...

Well, I would anyway

Cheers!

 

[Nick JD]

Here's a thread I did for people thinking exactly what you are, iralosavic.

http://www.aussiehomebrewer.com/forum/inde...showtopic=56285

It won't make all that much difference to your beer the first time round, but it will prove your techniques and give you confidence to do a triple decoction next time if you wish knowing your gear (and your brain) are up to it.

Most of this stuff is difficult before your try, and dead-easy after.

 

[DUANNE]

i say go for it and do a decoction up to maashout. one advantage of biab for a decoction is that all you need to do is lift the bag up and take a very thick part of thr mash to decoct and not worry about your enzymes which will be in the liquor not the grain anyway.also decocting up to mash out all your conversion will basically be done anyway so just think of it more as adding flavour than anything else. just one note though with the full volume mash using the thick part of the mash for decocting you will most likely not meet the temp target without giving the mash a tickle with an outside heat source.