Max Maize Gelatinisation Temperature?

[seravitae]

Hey there, was just wondering for anyone who gelatinises their own maize for brews, what temperature does this occur? I seem to be seeing gelatinisation temperatures for maize around 67-80C in food processing books however in practice on some other forums I noticed that people gelatinising maize do so as high a temperature they can get to cause the digestion.



cheers!

 

[Bribie G]

I'm thinking of doing a US or Mex style lager sometime soon to use up a couple of odd kilos of malt I have left and was thinking about rice / maize as an adjunct.

What sort of maize are you using? I had heard that polenta can be used. What's the difference between just gelatinising it and giving it a proper cook like you do for polenta?

 

[Fourstar]

I'm thinking of doing a US or Mex style lager sometime soon to use up a couple of odd kilos of malt I have left and was thinking about rice / maize as an adjunct.

I quite often do Cream Ales/CAPs with Corn/Maize and or rice.
Usually i will get the kibbled Maize/Rice (basically 2x the coarseness of polenta and is not pre-cooked). I simmer this down until the consistency of polenta (no hard bits) and dump into the mash for a standard sacc infusion of 60 mins. if the %ge of adjunct is over 30% i will usually extend this to 80 mins. FWIW, I have not found the need for a protien rest to aid in conversion, nor had any attenuation/starch issues so far.

I think Palmer said something about avoiding protein rests for fully modified malts as it can cause head retention/body issues. Considering you are adding 20-30% of adjunct it would probably end up quite thin if a protein rest was followed in conjunction with a grain bill such as JW malts. Usually my adjunct % is 20%~ and have no sparge issues either.

 

[seravitae]

BribieG,

I haven't used maize in beers before, i will when i get around to it. I only ask because I'm currently trying to work out the internal temperature limits for a heating controller im building. The controller will do mashing and distillation (where legal, controller will be for worldwide sale) temp controlling. On some home distilling sites using corn for bourbons they claim to gelatinise the corn at very high temps for very long times. I have heard of 100C / "max heating power" for 2 hours+ and also heard of >100C with pressure cookers/steam. Was just wondering how relevant these figures were to gelatinisation of maize for beer production..

Fourstar: Any idea what your 'simmmer' temperature is? I think that would be gelatinisation temp.



Cheers

 

[Fourstar]

I'd say the Gelatinisation temp would be atleast 100 deg C. With the thermal mass of the corn being relatively thick i would put 100 deg c as a minimum temp. Going from memory and checking the temp it was in the high 90's, 98~ after i had knocked off the flame before dumping into the mash tun but i cannot remember doing a temp reading whilst the corn was 'simmering'

 

[seravitae]

I'd say the Gelatinisation temp would be atleast 100 deg C. With the thermal mass of the corn being relatively thick i would put 100 deg c as a minimum temp. Going from memory and checking the temp it was in the high 90's, 98~ after i had knocked off the flame before dumping into the mash tun but i cannot remember doing a temp reading whilst the corn was 'simmering'

Yeah, thats what people are saying. I can't seem to find an upper limit though. It gets complex too, as the maize as a suspension doesnt contribute to raising the boiling point, but as the maize gelatinizes the boiling point will raise as stuff starts dissolving... *scratches head* I wonder if its possible for the temperature at standard pressure to be above 100 degrees as such.

 

[MHB]

Maize gelatinises between 62 and 77 C, it still needs to be boiled, see attached spreadsheet.



View attachment 24668
You can also get Flaked Maize, this is from Bairds, it's fully torrefied and is selected for brewing.

Brewing grade is chosen for lower glucan and protein levels just mix it straight in with rest of the grist.



MHB

 

[muckanic]

Neither maize nor rice contain significant enough protein to require a low temp rest. However, gelatinising in a limited capacity boiler can be a headache because of the high water absorption and consequently the scorch potential. Some folks perform a mini-mash before the gelatinisation step, as that converts just enough starch to keep the boil fluid. It is also recommended that the boiled or gelatinised goop is not allowed to cool down completely before the main mash, as it can reform viscous bonds that impede the mashing. Another thing a lot of folks do is soak the maize before the gelatinisation step to reduce subsequent water absorption.

 

[RobB]

I just use my daughter's pop-corn machine. I couldn't tell you what the temperature is inside that thing, but it's all over in a couple of minutes.

Or am I talking about something completely different?

If you do use popped corn as an adjunct, just be aware that it takes up a large volume for it's mass, although it dissolves pretty quickly.

 

[seravitae]

Yes you are talking about something different. I have never heard of popcorn (post-popped!) being used in beer. Interesting.




Thanks muckanic i didn't consider pre-soaking maize to prevent scortching - I actually had this issue a while back!

MHB thanks for the clear response. In that excel document the footnote says: * Starches or adjuncts made from these materials must always be cooked before mashing.

This is what confuses me. Everything points to 60-80C for gelatinisation temp, but then they also say "cook it /simmer it on full heat, so i'm still a little confused. Guess I'll just do an experiment soon and see.

Cheers guys.