Subbing polenta/corn grits revisited

[Shara]

I’ve read a lot about using polenta/corn grits as a substitute for flaked corn. I had a go yesterday and had major efficiency issues, which I believe was caused by my sloppy attempt at a cereal mash. Thought I’d share my experience to see what you think and to potentially warn others. (I will say this is only the 5th beer I’ve done solo, so I am very much a NOVICE brewer.)

There seems to be debate about whether or not you need to pre-cook the polenta or corn grits. Most of what I’ve read recommends that if they’re instant, then no, but if not, then yes. However I’ve also heard from a lot of home-brewers that you can just throw the polenta/corn grits straight into the mash regardless because the temp of the main mash should be high enough to gelatinize the grits.

I did a little bit of both (sloppy, I know), and my OG was way lower than expected. After going over the brew day, I assume my efficiency issues were caused by the grits not fully converting. I did a tank seven ish Saison/farmhouse

7.5 gallon
60 minute boil
Target OG: 1.077
Target FG: 1.013
- 3.5 K (7.7 lbs) Pale
- 3.5 K (7.7 lbs) Pilsner
- 1 K (2.2 lbs) Wheat
- 3 X680 g (4 lbs) Bob’s Red Mill Organic corn grits/polenta


I boiled a scoop of the pale and pilsner malt with 2 of the 680 g bags of grits. I stirred until mushy then added them to the main mash. I couldn’t fit the 3rd bag of grits in that pot, so I threw it directly into the main mash without precooking. I did a step mash starting at around 145 F and mashing out at 168 F.

Now, my thermometer dropped and the battery flew out, so I was running around trying to replace the battery and panicking that it was going to get too hot (with my husband yelling at me for being a crazy woman!). So I shut the heat off a couple times while I was stepping it up and it’s possible that the mash spent very little time in the upper 160s.

I did BIAB and sparged with about 2 and half litres. I expected an OG of 1.077 and got 1.056. Well, damn. I assume it’s because the grits didn’t fully convert? Or could it be that I didn’t get the heat high enough during the mash?

Either way, I am committed to properly pre-cooking the polenta/grits next time ☺. And thanks to all who have contributed a lot of very useful details on how to do this. I will take note for next time!

 

[helibrewer]

Corn gelatinizes in the 158-176F (70-80C) range so it must be cereal mashed before adding to the main mash for conversion.

 

[RM-MN]

I've used corn meal and dumped it into the mash without precooking it and got the same brewhouse efficiency as I usually do. I'd blame the wheat and the changing temperature before I'd blame the grits. Wheat berries are harder and smaller than barley so they require a tighter mill than barley. If you didn't take the extra care during the milling, your wheat didn't get you the sugars you should have.

 

[Shara]

I know there was a large fluctuation in temp throughout the mash and it is very possible that the Wheat was milled along with the Barley. (My homebrew store dude was in a rush to get the grain to me b/c it wasn't' ready when I arrived.)

So RM-MN - you've given me more to think about, thanks! Beyond properly milling the wheat, is there anything special with regard to temp. that you would do during the mash with a recipe that has a lot of wheat?

 

[RM-MN]

I know there was a large fluctuation in temp throughout the mash and it is very possible that the Wheat was milled along with the Barley. (My homebrew store dude was in a rush to get the grain to me b/c it wasn't' ready when I arrived.)

So RM-MN - you've given me more to think about, thanks! Beyond properly milling the wheat, is there anything special with regard to temp. that you would do during the mash with a recipe that has a lot of wheat?

Wheat has plenty of protein so it can cause chill haze or if not fully converted it will give you starch haze. Some people will do a protein rest to limit the protein going into the fermenter but you have to realize that some proteins help create the heading. For a beer that is supposed to be hazy to be to style, some recipes call for a tablespoon of flour at the end of the boil to ensure that there is enough starch to create the proper looking beer.

Chill haze caused by the proteins will settle out if your beer is chilled for a period of time. Starch haze is permanent.

 

[william_shakes_beer]

never mind

 

[Yooper]

to the OP;

your first post stated that you boiled the grits with a scoop of malted barley. This can creat problems.

When you mash grains that do not have diastic power (enzymes) you need to include some malt to include enzymes necessary to convert startch to sugar.

When you do a cereal mash you boil the cereal grains to geletanize the starches, then cool and put them in a mash with diastic grains to convert the geletanized starcheds to sugar. You should NEVER boil malt. First, it denatures the enzymes, rendering them useless, and second it extracts tannins which present as an undesirable aftertaste in the final beer. No need to add malt to the cereal mash.

A cereal mash does involved malted barley. You can cook the grains separately, but a cereal mash ensures conversion. It will certainly not extract tannins, as that has to do with mash pH and not boiling. Decoction mashing, for example, boils only barley and there isn't excessive tannin extraction. Same as true with a cereal mash- you boil the barley malt and the cereal grain together.

 

[william_shakes_beer]

A cereal mash does involved malted barley. You can cook the grains separately, but a cereal mash ensures conversion. It will certainly not extract tannins, as that has to do with mash pH and not boiling. Decoction mashing, for example, boils only barley and there isn't excessive tannin extraction. Same as true with a cereal mash- you boil the barley malt and the cereal grain together.

Yooper;

You've been around a lot longer than I, and I trust your judgement. Apparently I know less about all grain brewing than I thought I did, and have committed the cardinal sin of spreading incorrect information based on what I have "heard" from others. I am appropriately humbled.

I have not done a great deal of cereal mashes, usually brewing with malted grains and pre modified non diastic grains that do not require a cereal mash. I assume that if I boil the malt in the cereal mash I have denatured the enzymes, so what am I getting from the malted grains added to the cereal boil that I wouldn't get from adding them to the subsequent traditional mash?

 

[FourSeasonAngler]

Yooper;

You've been around a lot longer than I, and I trust your judgement. Apparently I know less about all grain brewing than I thought I did, and have committed the cardinal sin of spreading incorrect information based on what I have "heard" from others. I am appropriately humbled.

I have not done a great deal of cereal mashes, usually brewing with malted grains and pre modified non diastic grains that do not require a cereal mash. I assume that if I boil the malt in the cereal mash I have denatured the enzymes, so what am I getting from the malted grains added to the cereal boil that I wouldn't get from adding them to the subsequent traditional mash?

You should read up more on cereal mashing. - http://byo.com/bock/item/442-cereal-mashing-techniques

You only use a proportionate amount of milled barley (preferably 6 row) during the cereal mash process. After your cereal mash you add the boiled mash to your main mash tun.

 

[brew_ny]

I use corn meal and minute rice in the cream ale I brew

I just mash it all together in a bag in a cooler with the 2-row

my numbers have always been right on the mark

all the best

S_M

 

[wilserbrewer]

I have often wondered what benefit a cereal mash gives on the homebrew scale, versus simply cooking / boiling the unmalted adjunct grains? Surely there is enough enzymes to convert the adjunct starch when it is added to the main mash, so what purpose does the cereal mash provide?

In reading this morning, one thing I noticed that adding small amounts of malted barley to a corn or rice cereal mash will get some conversion started, and also improve the texture of the cereal mash to avoid a huge glue ball by adding husks and barley!

Perhaps on a commercial scale this is of greater benefit, but on a home brew scale, it has never been a problem to mix the gelled adjuncts back in the main mash. Does a cereal mash permit a higher percentage of adjunct grains?

FWIW, I have never done a cereal mash, but just have cooked the adjuncts very well prior to adding to the main mash.

On a homebrew scale, what benefit does a cereal mash serve, versus just cooking the adjuncts and adding back to the main mash, or is this another example of how the big boys do it. Or is there Maillard reaction benifit as well???

 

[Yooper]

I have often wondered what benefit a cereal mash gives on the homebrew scale, versus simply cooking / boiling the unmalted adjunct grains? Surely there is enough enzymes to convert the adjunct starch when it is added to the main mash, so what purpose does the cereal mash provide?

In reading this morning, one thing I noticed that adding small amounts of malted barley to a corn or rice cereal mash will get some conversion started, and also improve the texture of the cereal mash to avoid a huge glue ball by adding husks and barley!

Perhaps on a commercial scale this is of greater benefit, but on a home brew scale, it has never been a problem to mix the gelled adjuncts back in the main mash. Does a cereal mash permit a higher percentage of adjunct grains?

FWIW, I have never done a cereal mash, but just have cooked the adjuncts very well prior to adding to the main mash.

On a homebrew scale, what benefit does a cereal mash serve, versus just cooking the adjuncts and adding back to the main mash, or is this another example of how the big boys do it. Or is there Maillard reaction benifit as well???

You can cook the adjuncts and add to the main mash, assuming enough diastatic power. What is nice about a cereal mash is that it does facilitate conversion, as well as reduce the 'gumminess' of certain adjuncts. I get a slightly efficiency when doing a cereal mash vs not, for the same grainbill. Since you do BIAB, it's probably not a big deal for lautering, but I've noticed a much easier lautering with a cereal mash than with not using one.

I usually do a cereal mash only for large amounts of adjuncts, like in a cream ale where I may use corn and rice, or when using 40% unmalted wheat or something like that.

 

[RM-MN]

You can cook the adjuncts and add to the main mash, assuming enough diastatic power. What is nice about a cereal mash is that it does facilitate conversion, as well as reduce the 'gumminess' of certain adjuncts. I get a slightly efficiency when doing a cereal mash vs not, for the same grainbill. Since you do BIAB, it's probably not a big deal for lautering, but I've noticed a much easier lautering with a cereal mash than with not using one.

I usually do a cereal mash only for large amounts of adjuncts, like in a cream ale where I may use corn and rice, or when using 40% unmalted wheat or something like that.

I've done a cereal mash for oatmeal and it wasn't much different than what I get from just adding oatmeal to the mash but that may be because I mill my grain so fine. I tried a cereal mash with unmalted rye....once. That was enough. Cornmeal is already milled pretty fine so it gelatinizes fast at mash temps so it doesn't really gain from a cereal mash. Flaked corn would be different.

 

[Magnus314]

For rice, I've had great results just boiling the rice in plenty of water in the bag, then adding cool water to get down to strike temps and mashing in the barley into the ricey water.

And I've done the exact same thing with corn grits and it was a lumpy dough-glob horror show and low efficiency.

So there's a huge difference with different adjunct grains. I'll have to try cornmeal next time.

 

[joyceman]

Ive used cracked corn and rice twice in a light beer recipe. Both times I precooked it and tossed it into the mash (with a protein rest). It is a gooey lump mess that requires thorough stirring to break it up in the mash.

That being said, my numbers were equivalent to what I would have had if I had used flaked corn. I can get cracked corn for roughly 1/4 the price of flaked corn.

Theres a chart out there somwhere that give the temps at which various grains and adjuncts gelatinize. I dont want to post it cause its on a distilling board.

Edit:

Found it here...

https://www.homebrewtalk.com/f164/grain-gelatinization-chart-188872/