Maize Gelatinization Temperature - Polenta

[Bribie G]

I've been using polenta as an adjunct in some brews and from time to time I read comments that mash temperature (say 68 degrees) should be enough to gelatinize polenta without having to cook it up into a mush first.
I know there was a thread on gelatinization of maize about a year ago but I can't locate it. Does anyone know if polenta can just be added to the grist as-is?

 

[AndrewQLD]

62-70 for corn starches to gelatinize Bribie.
I would personally give it a boil prior to adding to the mash or you could well miss out on some conversion.

Andrew

 

[Fourstar]

62-70 for corn starches to gelatinize Bribie.
I would personally give it a boil prior to adding to the mash or you could well miss out on some conversion.
Andrew

As Andrew noted you can add it commando but for turnaround of gelatinisation and conversion times it htink it would be best to bring it do a boil or atleast rehydrate it like you do with dried legumes.

Here is something i pulled from the northern brewer forum a little while ago. :icon_cheers:

 

[reviled]

Tapioca? :icon_vomit:

 

[Zwickel]

Bribie, Im using Mais too once in a while, doing a light summer beer.

I found out, if youre using Polenta, you dont need to boil it prior mashing. Polenta is very fine, hence its easy to convert all the starch that is inside.

But if youre going to use whole corn grain or rough crushed corn, then you should boil it first.

Cheers :icon_cheers:

 

[Fourstar]

Tapioca? :icon_vomit:

nothing different from using potatos in a mash or pumpkin!

 

[Bribie G]

Tapioca? :icon_vomit:

Yes, tapioca pudding forced down your throat by an English Nanny then a good and deserved thrashing for being a naughty boy h34r:


Tell you what, based on the encouraging data in the above posts, in the service of investigative science, I'm mashing in shortly and I'll just add it to the grist but disperse it well with the malts - and see how I go. Worst that could happen is poorer conversion and a starch haze, but I'm only using 500g. With a bit of luck I'll now be able to avoid the messy exercise of boiling up in the stockpot, juggling temperatures and liquid volume when adding to the mash at dough in, and the scrub up of the stockpot etc after. Polenta is a brilliant idea but it's like cleaning up after a teen party afterwards <_< Also the temperature and other issues are very hard to calculate on the run when doing a full-volume BIAB, and hitting the right mash temp and mash volume can be a bit hairy.

 

[Nick JD]

Can someone explain "gelatinized"?

Is it a reaction of sorts - or can I just add rice/corn/starchy stuff as a powder? Having to boil adjuncts bites.

 

[Bribie G]

Can someone explain "gelatinized"?

Is it a reaction of sorts - or can I just add rice/corn/starchy stuff as a powder? Having to boil adjuncts bites.

Who can you trust if not Wikipedia : Linky :icon_cheers:

It's what happens when you use custard powder and that spoonful of dried powder swells to make a pan of gluggy custard or, when you cook rice, you end up with a mass of soft chewy stuff. What I'm looking at is to use stuff like Polenta which is a fine granule, almost a powder. To get it gelatinized does it really need to be boiled to a mush, or can it be converted to a state that can be eaten by the malt enzymes just at mash temperature ?

As you say, boiling in a stockpot is a PITA and if that stage can be eliminated by using starches that are finely ground (polenta, semolina etc) that can be converted at mash temps then that's got to be a time saver, as well as simplifying the brewing process.


Anyway: doughed in and will report in due course :icon_chickcheers:

 

[leiothrix]

Here is something i pulled from the northern brewer forum a little while ago. :icon_cheers:

Silly question - what do the asterisks mean? Also the small granules vs large granules, is that specific to anything, or just an indication that you're better off milling everything fine?

thanks,
rob.

 

[MHB]

You really should boil unmalted adjunct (unless you pay the extra for pre-done stuff), the fact that some of the gelatinisation range overlaps the mashing temperature doesn't mean that the adjunct you are using will gelatinise at the lowest possible gelatinisation temperature for that type of adjunct.

The starch granules we want to convert are locked up in a matrix of what is mainly B-Glucan, you can think of it as trying to get the aggregate back out of a concrete block, if you dissolved the cement away with acid the blue metal would be free, that's similar to what happens during malting, the cement is broken down, the enzymes (A&B Amylase and others) can then act on the starch to make sugar.

I guarantee you can't mill fine enough to make much difference so boil the stuff or buy brewing ingredients made for the job.

Here are a couple of links with pictures and all Starch / Rice , More Starch

MHB

 

[Thirsty Boy]

back up what MHB says -

Starch molecules are wound up into tight little spiral type structures - when heated to the right temperature, they unwind. Amylase Enzymes work (descriptively) by fitting themselves up against a matching bit of a starch molecule, like two jigsaw puzzle pieces fit together.. if the starch molecule is still all wound up tight.. the enzymes can't nestle in to do their work, so the starches must be unwound (gelatinised) before enzymes can have any real effect on them.

Here's a nice little explanation

http://cdavies.wordpress.com/2006/10/05/starch/

I just use "instant" polenta which is pre-gelatinised. Otherwise I'd properly cereal mash or at least pre-cook any raw corn or rice adjunct, really should with any raw adjunct.. but I don't worry with wheat, barley etc.

Oh - and I have made a beer with tapioca as a starch adjunct.. it was perfectly good.

TB

 

[Nick JD]

Who can you trust if not Wikipedia : Linky :icon_cheers:

It's what happens when you use custard powder and that spoonful of dried powder swells to make a pan of gluggy custard or, when you cook rice, you end up with a mass of soft chewy stuff. What I'm looking at is to use stuff like Polenta which is a fine granule, almost a powder. To get it gelatinized does it really need to be boiled to a mush, or can it be converted to a state that can be eaten by the malt enzymes just at mash temperature ?

As you say, boiling in a stockpot is a PITA and if that stage can be eliminated by using starches that are finely ground (polenta, semolina etc) that can be converted at mash temps then that's got to be a time saver, as well as simplifying the brewing process.


Anyway: doughed in and will report in due course :icon_chickcheers:

So it's got nothing at all to do with gelatin or proteins or pig's feet, eh? How cornfusing! Cheers.

Another useless "brew word" to scientifically blind me. From here on I will use the ancient Chinese technical verb, "congeefy".

Wouldn't fine cornflour (the corn stuff) be gelatinized at mash temperatures?

 

[Thirsty Boy]

Wouldn't fine cornflour (the corn stuff) be gelatinized at mash temperatures?

Not particularly so - unfortunately - its gonna get pseudo scientific again

In an unmalted grain - the starch is bound up in a protein matrix. Basically its surrounded by the stuff. If you just plonk big chunks of unmalted grain into a mash.. even before you worry about gelatinisation, you have to get the starch out of its protein matrix and into the open, where it can gelatinise and then be broken down by the enzymes.

In the malting process - the natural germination of the grain, breaks down the protein matrix and exposes the starch. Thats what they mean when they say "modified" it means the extent to which the insoluble proteins in the grain have been turned into soluble ones that allow access to the starch granules.

Now if you are using unmalted corn grits.. you do a cereal mash on them. This involves boiling the crap out of them, and this breaks up the protein matrix. Or if you are using a corn (or any other sort of) flour, then the milling process physically exposes the starch granules.

BUT - none of that gelatinises them.

In a flour - the particles are very small, they will hydrate very quickly and they will heat up very quickly... so gelatinisation will be very fast and efficient, but is still at the heart of it temperature dependent. So while it will happen better at mash temperatures than it would with a courser particle... it might well still not happen properly.

And besides - flours are a nightmare to use in a mash, even a BIAB one. You need to do a good beta glucan rest on the *******s to make them workable and therefore if the object of using flours is to avoid extra mucking about.. it's a self defeating proposition.

 

[Fourstar]

Silly question - what do the asterisks mean? Also the small granules vs large granules, is that specific to anything, or just an indication that you're better off milling everything fine?
thanks,
rob.

You know what... i have NFI! :icon_cheers: obiosuly something they all have in common... but what?

 

[Thirsty Boy]

Its gonna take more brewing science I'm afraid.....

I don't know what the asterixs mean though.

Starch in Barley comes in granules - the granules come in two different sizes

Small - 1-5m which make up 90% of the number of starch granules, but only 10% of the total starch content
Large - 10-25m, which are only 10% of the numbers but 90% of the total content.

As you can see from fourstar's chart above - the two different types of granules gelatinise at different temperatures. Fret not though ... small granules are preferentially converted during grain germination, and a goodly chunk of them don't make it through the malting process unconverted. so the starch in malted barley - is even more "mostly" in the form of large granules and thats why the normally quoted gelatinisation temperatures for malt starch are in the low 60's

Enough poorly related science for ya??

Thirsty

 

[Bribie G]

Update. Twenty minutes ago I kegged the beer after 2 weeks primary and 2 weeks lagering, gelatine and polyclar. Not the best photo, very humid here ATM and the glass frosts intantly at 3 degrees - but if you look near the base of the glass you'll see it's gone into the keg very clear indeed and will only get better - I'll be sure to post a pic in what's in the glass over Xmas.



The final grain bill was:

4000 BB Galaxy
500 Polenta Raw

66 degrees 90 mins.

The exercise has convinced me to just use the polenta 'raw' from now on. It's a great little adjunct and the black and gold variant at $1.20 a packet stacks up well against flaked maize at twice the price.

 

[warrenlw63]

Update. Twenty minutes ago I kegged the beer after 2 weeks primary and 2 weeks lagering, gelatine and polyclar. Not the best photo, very humid here ATM and the glass frosts intantly at 3 degrees - but if you look near the base of the glass you'll see it's gone into the keg very clear indeed and will only get better - I'll be sure to post a pic in what's in the glass over Xmas.
View attachment 34100


The final grain bill was:

4000 BB Galaxy
500 Polenta Raw

66 degrees 90 mins.

The exercise has convinced me to just use the polenta 'raw' from now on. It's a great little adjunct and the black and gold variant at $1.20 a packet stacks up well against flaked maize at twice the price.

View attachment 34101

Geez that's awesome Bribie. I've often wondered what would happen if you just added it to the mash. Are you totally convinced the polenta converted? ie; are your brewhouse efficiency figures in line with what you predicted etc?

Thanks for sharing that.

Great looking beer already BTW.

Warren -

 

[Fourstar]

Geez that's awesome Bribie. I've often wondered what would happen if you just added it to the mash. Are you totally convinced the polenta converted? ie; are your brewhouse efficiency figures in line with what you predicted etc?
Thanks for sharing that.
Great looking beer already BTW.
Warren -

That was my expectation too when i did it, although I used a kg and mine was slightly under. Denny Conn does it from what i remember and doesn't run into any problems. There may be a difference between raw polenta and the instant variety when you use it in high % of your grist.

 

[Bribie G]

No I didn't take accurate measurements, which obviously I should have done. However the spent grain showed nothing but husks and the wort tasted very sweet, as I find when using either polenta or rice, so I'm confident that it all converted. I'm doing two Stella Artois type attempts in succession so using a bit of polenta, Saaz and Styrians, and will pay closer attention next time.

Edit: the purpose of the exercise was mainly to see if I got a starch haze, which would have been a true giveaway, now I can look at the conversion issues. :icon_cheers: