Gelation vs. Cereal Mash

[Black Island Brewer]

Whenever I start poking around with non-enzymatic cereal grains in brewing that don't gelate at mash temperatures (rice, corn) I often come back to something I've never quite been able to wrap my head around.

In order to break up the starch matrix of a high-gelation temp cereal grain, the recommendation always seems to be to do a cereal mash, where the cereal grain is mashed with enzymatic malt at mash temps, then boiled to break down the starches. Why two steps? Why not just boil the cereal grains right from the get-go? Is something else happening at mash temps that is required for gelation to occur?

The reason this bugs me is that flaked and torrified cereal grains are said to be "pre-gelated" with pressure and heat, but I assume they haven't been mashed with enzymatic malt first. Why not just grind your corn or rice and then bring to a boil until it breaks down?

Thanks, oh great homebrew collective, for your wisdom!

 

[Yooper]

Whenever I start poking around with non-enzymatic cereal grains in brewing that don't gelate at mash temperatures (rice, corn) I often come back to something I've never quite been able to wrap my head around.

In order to break up the starch matrix of a high-gelation temp cereal grain, the recommendation always seems to be to do a cereal mash, where the cereal grain is mashed with enzymatic malt at mash temps, then boiled to break down the starches. Why two steps? Why not just boil the cereal grains right from the get-go? Is something else happening at mash temps that is required for gelation to occur?

The reason this bugs me is that flaked and torrified cereal grains are said to be "pre-gelated" with pressure and heat, but I assume they haven't been mashed with enzymatic malt first. Why not just grind your corn or rice and then bring to a boil until it breaks down?

Thanks, oh great homebrew collective, for your wisdom!

The cereal mash is held at gelatization temperatures for conversion. That happens before the boiling/cooking part.

 

[SnakeRidge]

I use quick grits in place of flaked corn in a lot of brews. I always boil the grits in water to gelatinize, basically like I would for eating. Seems to work fine, I get the same efficiency with flaked corn and the boiled grits. I looked into cereal mashes and it just seemed like a huge pain to have two mashes going at once so I skipped it and went straight for the boil.

 

[Black Island Brewer]

The cereal mash is held at gelatization temperatures for conversion. That happens before the boiling/cooking part.

Is conversion necessary? Since most of the starches are still locked up, why conversion THEN boil. Why not just boil, then convert in the main mash?

 

[Owly055]

The cereal mash is held at gelatization temperatures for conversion. That happens before the boiling/cooking part.

Note that the article below supports the OP's point, and I suspect is how most of us treat these grains....... I'm sure I'm not the only one here who cooks these grains before mashing. The proof is in the pudding as they say. I get the expected gravity from these grains doing it this way............

H.W.

Gelatinization Temperatures for Adjuncts
Posted to HBD #2092, 7/9/96,
by Rob Lauriston, [email protected]
Gelatinization of barley starch has been mentioned recently, and people periodically ask about how to treat adjuncts. The following is from "Malting, Wort Production and Fermentation", which is volume 2 in "An Introduction to Brewing Science and Technology (Series II)" from The Institute of Brewing.




Gelatinization temperatures of starches
_______________________________________

starches gelatinization temperatures 'C

maize 70-75
sorghum 70-75
rice 68-75
wheat 52-54
barley 61-62
potato 56-69

"[The table...] illustrates why some adjuncts are cooked and others are not. Since starch conversion in the mash tun occurs most efficiently at about 63-65'C, those starches which gelatinize above 65'C would yield little extract if they were not heated beyond 65'C (or cooked) to ensure general liquifaction. Maize, rice or sorghum grits are usually cooked with 5% malt (or heat-stable alpha-amylases) to keep the cooked grits in a liquid form. The cooked grits are then transferred to the mash mixture for conversion. The alpha-amylase of the malt is responsible for the liquefaction during cooking." pp.50-51.

 

[SnakeRidge]

I should add that I dump the boiled grits into the main mash, so conversion happens there. I don't see the point in converting the cereal, boiling and then adding that back to the mash. As long as the starches are 'free' then I imagine conversion in the mash takes care of it.

The first time I used quick grits, I didn't boil, just added to the mash and did not get conversion (efficiency was way low).

 

[Yooper]

Is conversion necessary? Since most of the starches are still locked up, why conversion THEN boil. Why not just boil, then convert in the main mash?

Sure, you could do that. Most of the conversion happens in the main mash, and not the cereal mash.

Boiling the cereal grains and then mashing will generally give better extraction, but often it's simply to speed up hydration of the grains.

Some stray starches will convert at the gelatinization temperatures, though, and that is why it's traditionally held a the gelatinization temperature before boiling/cooking the adjuncts. It makes the cereal grains/cereal mash more fluid.

 

[billl]

It's a holdover that probably doesn't make much difference on a homebrew scale. Modern malts have way more enzymatic potential than old malts. They used to take some 6-row and mash it with the adjuncts to get as much conversion as possible before boiling. That way, the the lower power 2row in the main mash wouldn't have as much to convert. You can try it side by side on your next brew and see if there are any differences.

One benefit of the mash-first approach is that the mash loosens up and becomes more fluid. That will help keep it from scorching as you bring it to a boil. If you aren't going to do it, you might want to add additional water so you aren't just making oatmeal.

 

[Black Island Brewer]

It's a holdover that probably doesn't make much difference on a homebrew scale. Modern malts have way more enzymatic potential than old malts. They used to take some 6-row and mash it with the adjuncts to get as much conversion as possible before boiling. That way, the the lower power 2row in the main mash wouldn't have as much to convert. You can try it side by side on your next brew and see if there are any differences.

One benefit of the mash-first approach is that the mash loosens up and becomes more fluid. That will help keep it from scorching as you bring it to a boil. If you aren't going to do it, you might want to add additional water so you aren't just making oatmeal.

This makes a lot of sense to me.I hadn't considered that the DP of the main mash might be a concern.

I think I'll try going straight to boiling, like when I make polenta or risotto, but keep it thin like you suggest.

 

[Yooper]

This makes a lot of sense to me.I hadn't considered that the DP of the main mash might be a concern.

I think I'll try going straight to boiling, like when I make polenta or risotto, but keep it thin like you suggest.

That would work, especially if you keep the adjuncts to 30% or less, or calculate out the DP to ensure conversion.

 

[Black Island Brewer]

That would work, especially if you keep the adjuncts to 30% or less, or calculate out the DP to ensure conversion.

Definately. DP of 40 or more, IIRC. I'm that guy who got the lot analysis so I'd know the specific DP and not just the average. When I make my next cream ale, I'll post my results (using white rice and corn meal).

 

[Yooper]

Definately. DP of 40 or more, IIRC. I'm that guy who got the lot analysis so I'd know the specific DP and not just the average. When I make my next cream ale, I'll post my results (using white rice and corn meal).

I used Minute Rice for my last cream ale. It was on sale on the Dollar Store, so I got like 32 oz for $1, and it worked great (with no cereal mash or cooking.............:cross

 

[ba-brewer]

For doing just gelatination would you use the same 2 or 3 qt of water per pound of cereal as a cereal mash? Also how long would you need to boil it?

 

[joyceman]

For doing just gelatination would you use the same 2 or 3 qt of water per pound of cereal as a cereal mash? Also how long would you need to boil it?

When Ive gelatinized corn (cracked corn) and rice, Ive gone with the cooking instructions for rice 1:2 ratio of corn/rice to water. Bring to a boil and simmer until all water is absorbed. Usually around 20-30 mins on low heat.

 

[SnakeRidge]

For doing just gelatination would you use the same 2 or 3 qt of water per pound of cereal as a cereal mash? Also how long would you need to boil it?

When I boil grits (for beer, not breakfast!) I do a pound in a gallon of water. Any less water and it turns into a mess. I figure it in my infusion mash and add it with the strike water. I boil for 20-30'.

 

[judsonp]

The important part of a cereal mash is starch gelation. All you need in order to accomplish this is to boil the hell out of the grain. The boiled grain then goes in with your mash like any other ingredient -- just like torrified and flaked grains have been pre-treated so that the starches are soluble in the mash, now your boiled grain has been treated so that the starches are soluble in the mash. The starches get broken down in the mash... you know the rest.

No malt or holding at a particular temperature is necessary for the cereal mash.

The reason that adding malt and giving it some time at a conversion temperature is often recommended is that it makes the cereal mash easier. You'll perhaps notice that if you don't include malt, either you have a very high water-to-grain ratio or it sets up into a thick porridge that's difficult to work with. Well, while the starch gelation doesn't finish in a reasonable time except through boiling, a lot of the starch is released well below the boiling point. By including some malt in the cereal mash, the enzymes in the malt will act on a lot of that starch, helping keep your mash from being a gooey mess.

I personally just use a lot of water. I figure out how much cold and boiling water I need to mix together to hit my strike temperature, and do the cereal mash with the "boiling water" volume. That was enough to support 2 pounds of corn grits (for 5 gal) while still remaining fairly thin.

 

[IslandLizard]

John Palmer has a really good section on cereal mashes that answers all the questions. (How to Brew, 2006, pp.173-75)

"You can gelatinize the starches by just boiling them, but you can do it more effectively by using a combination of enzymes and heat...."

"Gelatinization is not like being pregnant...."

 

[RM-MN]

I found a couple other charts with gelatinization temperature ranges that were way different than the one posted above.

http://homedistiller.org/forum/viewtopic.php?f=3&t=16799
http://www.winning-homebrew.com/cereal-mash.html

Both of them show that the gelatinization temperature of corn is in a much wider range with the bottom for corn at about 145 and rice at about 142. I've milled the white rice fine and used cornmeal without any cereal mash and got full conversion from them as they gelatinize in the mash.

 

[Black Island Brewer]

So, I'm out in the yard working on my gardens, thinking about the next cream ale I'll make, based on Cream of Three Crops by Biermuncher, and I think to myself, "Self, I'll bet you could put plain old cornmeal and ground up white rice in a crock pot with some water and just let it go overnight. It would be ready to go by the next morning, and you'd just have to adjust the strike temp to account for the temperature of the corn and rice grist." And then I thought "...and if you put in one of those crock pot liners, you could just lift it out of the pot and dump it in". And then I thought "You could call it 'Crock Pot Cream'." I crack myself up.

 

[ba-brewer]

Thanks everyone for their comments about the amount of water and boil times. I have some indian corn we grew in the backyard that I have been thinking about using in a cream ale. Glad to hear there are easier ways to make use of cereal then doing a stepped cereal mash with malt.

 

[judsonp]

I found a couple other charts with gelatinization temperature ranges that were way different than the one posted above.

http://homedistiller.org/forum/viewtopic.php?f=3&t=16799
http://www.winning-homebrew.com/cereal-mash.html

Both of them show that the gelatinization temperature of corn is in a much wider range with the bottom for corn at about 145 and rice at about 142. I've milled the white rice fine and used cornmeal without any cereal mash and got full conversion from them as they gelatinize in the mash.

Yeah. As I understand it, the starch gelation temperature for cereals is relatively low. The boil is needed to break down the structure of the cereal enough to enable gelation. So if you grind it fine enough, you should be fine.

I'm curious how effective that can really be, though, even with "finely" ground flour. Standard wheat flour takes a fair bit of heat to get it to gelate. How is it you're testing for full conversion of the grain?

So, I'm out in the yard working on my gardens, thinking about the next cream ale I'll make, based on Cream of Three Crops by Biermuncher, and I think to myself, "Self, I'll bet you could put plain old cornmeal and ground up white rice in a crock pot with some water and just let it go overnight. It would be ready to go by the next morning, and you'd just have to adjust the strike temp to account for the temperature of the corn and rice grist." And then I thought "...and if you put in one of those crock pot liners, you could just lift it out of the pot and dump it in". And then I thought "You could call it 'Crock Pot Cream'." I crack myself up.

That should work.

 

[RM-MN]

Yeah. As I understand it, the starch gelation temperature for cereals is relatively low. The boil is needed to break down the structure of the cereal enough to enable gelation. So if you grind it fine enough, you should be fine.

I'm curious how effective that can really be, though, even with "finely" ground flour. Standard wheat flour takes a fair bit of heat to get it to gelate. How is it you're testing for full conversion of the grain?



That should work.

Rather than a direct test for conversion I use two indicators. With the recipe I used the corn and rice contribution were 33% of the weight of grain in the mash. Without full conversion I could not have reached the predicted OG. Since I was able to get the predicted OG there must have been pretty conplete conversion. The second indicator is the lack of starch haze in the beer. The beer turned out crystal clear which wouldn't have been possible if there was still starch in it.

 

[judsonp]

Rather than a direct test for conversion I use two indicators. With the recipe I used the corn and rice contribution were 33% of the weight of grain in the mash. Without full conversion I could not have reached the predicted OG. Since I was able to get the predicted OG there must have been pretty conplete conversion. The second indicator is the lack of starch haze in the beer. The beer turned out crystal clear which wouldn't have been possible if there was still starch in it.

The second test might be tricky -- gelation is what gets the starch into solution, so incomplete gelation might not give you haze. (Haven't tried it, not sure.) That's the same problem you could have with a direct test -- the starch could still be inside unhydrated grains rather than in the liquid you test.

But if you get your OG as estimated with such a big grain component, it obviously worked. Who could ask for more? Neat.

 

[Yooper]

So, I'm out in the yard working on my gardens, thinking about the next cream ale I'll make, based on Cream of Three Crops by Biermuncher, and I think to myself, "Self, I'll bet you could put plain old cornmeal and ground up white rice in a crock pot with some water and just let it go overnight. It would be ready to go by the next morning, and you'd just have to adjust the strike temp to account for the temperature of the corn and rice grist." And then I thought "...and if you put in one of those crock pot liners, you could just lift it out of the pot and dump it in". And then I thought "You could call it 'Crock Pot Cream'." I crack myself up.

More like 'crack pot cream ale'.

Just sayin'.

I love that no matter what else you're doing, like working in the garden, you're thinking of brewing. I do that too.

We'll be driving on a road trip, and my husband will suddenly say, "You've been very quiet. What is on your mind?" and I will startle and think, and then say something like, "If I mash the next maibock without a protein rest, but instead do two saccrification rests, like a Hochkurz decoction schedule and change the temperatures to something like 146 and 156, I bet that would make that recipe even better."

 

[Black Island Brewer]

More like 'crack pot cream ale'.

Just sayin'.

I love that no matter what else you're doing, like working in the garden, you're thinking of brewing. I do that too.

I have brewed thousands of batches in my head over the years. It's worse now, because while doing other things I'm listening to brewing podcasts, have Beersmith and HBT on my phone, my homebrewery on Facebook and Untappd, and teach homebrewing at the local CC. So my thoughts are almost along the lines of "You Know You're a Homebrewer When". Thankfully, my beautiful wife has amazing powers of distraction.

 

[Owly055]

I've done white rice with a fine crush (.010) and gotten no conversion whatever in the mash..... I haven't tried corn meal though. Quick or minute rice, or something on that order is already partially precooked, so I would expect far different results....... I'm not buying the idea that rice will convert properly without heating it to a higher temp......... based on experience.

I base conversion on the numbers Brewer's Friend gives... I know what to expect from my malted grains from experience..... I get a brewhouse efficiency in the low 80's typically, or more depending on my process. It's easy to just drop the rice and look at what the OG should be for a comparison.......... Perhaps if the rice is ground to flour it might work....... It clearly does NOT work with an .010 crush, and does work if the rice is cooked.



H.W.

 

[ba-brewer]

Made a 3gal batch of Indian Corn Cream Ale over the weekend, using gelatinization instead of a cereal mash.

Ground my pound of indian corn kernels using a coffee grinder. The consistency was mostly flour like with some bigger chunks. I threw it in a 5gal pot with 1.5gal of cold water then heated it to a low boil for 40mins. Glad I did it outside as somewhere around 25min it foamed up and overflowed a little bit.

I added some more water and brought the temp back up to the strike temp then added that with the rest of the grain into my mash tun and mashed as normal. I got 73% brew house efficiency which is close to my norm of about 75%.

I have brewed a few cream ales and never really detected any corn flavor in the wort before, but I could on this one. I dont know if this was because of the variety of corn or boiling the corn the in mash water or because corn made up 17% percent of the grain bill where other were closer to 10%.

The consistency was getting sort of thick at the end of the boil, so I can appreciate why someone might do a cereal mash to thin it down some, but if I were to do it again I think I will just start with a little more water.