Stepped Mash Infusion

[manticle]

Also maybe worth noting that mash thickness and pH play a role in enzyme activity. Temp is most often spoken about and probably should be considered the prime but not sole candidate.

 

[labels]

Also maybe worth noting that mash thickness and pH play a role in enzyme activity. Temp is most often spoken about and probably should be considered the prime but not sole candidate.

Agreed, especially pH unless grain:water ratio is absurd when it takes over

 

[mje1980]

I did a hochkurz style step with my latest batch of helles. 63-30 mins, 72-30 mins. The result is a light body highly attenuated lager that has very good malt prescence. Its hard to explain, but it is light bodied, but has good mouthfeel, i hope that makes sense?! I doubt i could have got the same result without the step. Light bodied and highly attenuated sure, but not with the same nice maltiness.

I only really step for beers like kolsh, helles and i do a ferulic rest for weizens, but for ales, i just do a single infusion, then finish with a short 72c rest, which adds good head retention ( thanks manticle! ). I did try a step mashed brown ale, which was nice, but i don't think i need to do it for ales, maybe a really big ale i might, to ensure attenuation.

 

[QldKev]

There's been so much focus on mash scheduling that a few important things have been left unsaid... Exclusive infusion mashing is a technique that can quickly and easily go wrong - many learn thus by experience, including me. If your strike in water temp or calculation is out, each subsequent volume and temp will become more and more out too. So here's a couple of tips:

Stir you HLT water to ensure consistent temp prior to filling for strike.
Agreed

Preheat your MLT with a kettle of boiled water, as the material temp is usually way colder than anticipated and also tends to absorb more heat than calculated.
I use Beersmith and find it is actually really good at getting this correct

Once your strike water is in the MLT, stir it and double check its temp - you aren't under pressure until you add the grain, so be certain first.
Only problem here is I add my grain to the mash tun first, and underlet.

Keep a boiled kettle and a pail of cold water at the ready for emergency adjustments.
For people with HERMS/RIMS, what I do is always set the HLT to a degree cooler than the calculated temp. The heat exchanger gets the temp correct within a minute which is bugger all conversion time.

Try to relax and don't expect things to go to plan, but be prepared to take notes so that you can iron out any miscalculations next time.
Notes are excellent, I still jot down bits and pieces on brew day.


Good luck and have fun!

Added a few comments inline.

 

[pk.sax]

@ Lecterfan

Cooling down the mash is exactly what you do with a decoction. The portion mashed higher is dumped back into the cooler bulk to increase the temp of the cooler main mash but in turn the already broken down dextrins in the decoction are brought down to the 62-63 C range. Best of both worlds.

If Tony wheeler had a good run of chilling his mash tore-create that without decocting, that'd be definitely something to try.

 

[Charst]

Hmmm so not totally cut and dried? Anyone with sources to point me towards?

there is a basic brewing podcast episode dedicated to reverse mashing

the show
http://traffic.libsyn.com/basicbrewing/bbr...reversemash.mp3

the guests blog
http://seanterrill.com/2011/03/27/reverse-mashing/

 

[QldKev]

I tried reverse mashing once, I successfully converted my beer into grain...

 

[manticle]

@ Lecterfan

Cooling down the mash is exactly what you do with a decoction. The portion mashed higher is dumped back into the cooler bulk to increase the temp of the cooler main mash but in turn the already broken down dextrins in the decoction are brought down to the 62-63 C range. Best of both worlds.

.

Different kettle of fish though. The starches in the decocted portion are broken down by the boiling process. Going back to 62 won't reactivate the beta-amylase which will definitely have been denatured during decocting. Going from 68 to 62 on the other hand will alter the optimal conditions and beta will be favoured in the second round.

Thing to remember is that enzymes operate under all sorts of conditions, including temperature. There is a range of conditions which are optimal for various enzymes but they can still operate outside that range and even once they hit denaturing temperatures, not all enzymatic activity will cease immediately. That's why mash-out is upwards of 77 degrees and is held for 10 or so minutes (for those that do it).

 

[Yob]

PH related question..

So having the ability to step mash lends itself to an acid rest (at least being able to) for a beer in the lighter style? Ive been thinking it does but have a little acidulated malt I want to try first.. I guess having the ability to step lends itself to further experimentation

out of curiosity, if I wanted to do an acid rest at say 38'c how long would it be for?

Id like to be able to stop using citric acid to bring PH down if I could just do it in a rest

:icon_cheers:

 

[seamad]

IIRC it takes an hour or so to drop pH by a meaningful amount. I use between 1-2% acid malt in most brews plus some calcium salts and after some trial and error can nail pH for most new recipes now.

 

[manticle]

...... Principles of Brewing Science (ed II). In that book, Fix suggests that the acid rest (35-40) is fairly redundant as while acid forming enzymes are active between 35-40, their effect on pH is counteracted by the buffering capabilities of the mash

^From an earlier post. Not 100% sure beyond that bit of literature though. Never tried one myself - might be an interesting experiment to do at home with 100% pale malt and Melbourne water (or RO water). I know the experiment has likely been done (Fix just refers to 'practical experience').

Will check some other texts and see if there is any further reference.

Had a quick look through Lewis & Bamforth and could only find reference to acid additions as a strategy to reduce mash pH.

Braukaiser mentions it in passing

The mash pH can also be affected by the chosen mash schedule. The boiling of mash in decoction mashing, for example, lowers the mash pH. I have seen a pH drop of up to 0.2 pH units during decoction mashing. This decrease of mash pH might be attributed to the enhanced precipitation of calcium and magnesium phosphates [3].
A rest between 30 and 40 C (90-110 F), known as acid rest, promotes phytase activity which releases more phosphates into the mash. While this is said to acidify the mash I have not observed a significant mash pH decrease though the use of this rest

from here: http://www.braukaiser.com/wiki/index.php?t...Mash_pH_control.

Interesting about the effect of decoction on pH. I presume he has taken into account temperature effect on pH measurement..

Noonan (New Brewing lager beer) talks about it in a couple of pages - seems to relate to undermodified pale malts and a decoction schedule and only when using water that is high in carbonates. Melbourne water certainly isn't so you might succeed if decocting a paler coloured lager/pilsner.

All a bit hither and thither really.

 

[Florian]

Lecterfan - start with George Fix - principles of brewing science, easily and cheaply available from book depository. Last few pages of chapter 1, 2nd edition.

:icon_offtopic:

I'd recommend booko.com.au for all books, it actually compares most online book vendors and you will find that you can get said book for $5 less (or $7 less in used condition) than on book depository.

 

[manticle]

:icon_offtopic:

I'd recommend booko.com.au for all books, it actually compares most online book vendors and you will find that you can get said book for $5 less (or $7 less in used condition) than on book depository.

Good tip. Cheers.

If you go through the Melbourne Brewers brewclub website to buy books from BD, we get a small cut back that allows us to buy books for our lending library. I'll have to suggest they try and hook up something similar with booko.

 

[pk.sax]

Tickleman, what I meant was that while everything in the decocted portion is prolly denatured, the undecocted part provides the beta amalyse to do the needful to the combined mash.

 

[manticle]

If you haven't already rested the to be decocted portion at beta rest temps (I do) then the boiling process should break down the starch as far as my reading tells me.

The remainder of the mash is just converting itself with its own beta. Surplus diastatic would take care of unconverted starch in the decocted mash IF the main mansh had some and IF you added the decocted to hit beta rest temp. Lecterfan was wondering if you could move from an alpha amylase rest to a beta amylase rest so I'm not sure I follow you on this. Can you elaborate?

 

[Steve@PMF82]

Tickleman, what I meant was that while everything in the decocted portion is prolly denatured, the undecocted part provides the beta amalyse to do the needful to the combined mash.

Interesting thread none the less

BUT i vote for a name change! Tickleman for the win :lol:

 

[pk.sax]

Hmnnnnnn. I'd use the decoction to step from protein to beta. Basically take a decoction at the time of starting a protein rest and then using the short rest time to decoct and add back to get to 62C. Then another to hit 68. I see no point in holding the to be decocted at no using decoction to hit 62. From what I understood, the great part is that the decoction goes through the various stages somewhat quickly, especially useful being the alpha stage that provides medium length sugars to the beta phase when added back to main mash. Then again mate, I've only done 2. They did attenuate very well despite being higher gravity and my yeast practices being nothing special.

What lecter asked was to bring down to beta from amalyse rather than from beta to amalyse. I'd assume he would do a direct infusion to 68 and then drop to 62, which would make it sort of analogous to a decoction...

Tickle on

PS: what's this talk of the boil breaking down starches. Isn't that the job of the mash?

 

[manticle]

PS: what's this talk of the boil breaking down starches. Isn't that the job of the mash?

Decoctions can be taken at various points. How long is your protein rest and with what malt?

Will have to try and dig up a reference or two but from what I've read, one of the effects of boiling grain is that it will break down starch into shorter chains - thus replicating the work carried out by saccharification enzymes.

 

[pk.sax]

Never did a protein rest longer than 15min. Like implied above, hit protein rest with infusion, take decoction and boil, add back to hit 62. Take decoction straight away and boil, add back to hit 68.

From my reading and some posts or maybe braukaiser it is the alpha stage during the decoction (gradually bring to boil vs quickly) that breaks down the starch. From practical experience, the conversion happens very very fast and the bit of time in alpha during decoction should suffice.

 

[Byran]

I think this Diagram shows most of the information everyone has been talking about. And yes, listen to manticle, he knows heaps of beer stuff N that.
View attachment 58257 :drinks: