An Introduction to Doing a Cereal Mash

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Many all-grain brewers seem to be put off when anything beyond a single infusion comes up in a recipe. Terms like “triple decoction” conjure up images of steampunk laboratories, mad scientists, and hump-backed henchman. Cereal mashing seems to get the same response, which is understandable as just about every article on the subject is filled with diastatic calculations, gelatinization temps, etc. which no one having a beer on brew day wants to remotely contend with.
At this point, I should tell you that the benefit of cereal mashing is simply that you, by adding an hour or less to your brew day, will be able to use any grain, flour,or other cereal in your beers without exception. Wheat flour, corn meal, sorghum porridge, millet flour, Ethiopian teff, triticale meal, rye flour - even garbanzo bean flour (if you happen to be so inclined)! Considering the versatility of this simple process and what it could do for all home brewers, I did the noble thing and booted all the science out the window! Here I'll present you with just the bare-bones process in 4 easy steps. Should you be feeling somewhat intelligent, which might include the homebrew-imbibed type, there is a “DETAILS” section after each step which explains what and why we are doing what we're doing. The only calculations you will be doing are the ones you already do in all-grain brewing on a single infusion recipe, and I have included a recipe of a delightfully crisp Cream Ale to practice with. Well, let’s get on with it then…
Almost kind of flour or un-malted grain can be used for a cereal mash.

Extra Equipment You’ll Need:


An extra 3 gallon or larger pot (extremely technical, I know).
A note regarding your adjunct of choice: Whatever grain you choose to add to your beer, it is highly recommended that you grind it as fine as possible – or you could just buy it ready made as either a meal or flour. For example, in this type of procedure corn meal is preferable to corn grits because it’s been ground finer and you’ll get a bit more out of it.
A note regarding the amount of barley to use in the cereal mash: Simply take the weight of all the barley malt for the recipe, remove 10% of it and add it to the cereal mash pot.

STEP 1: The “Dump Everything in a Pot” Step


What we're are actually doing? We are making a thin, watery porridge from your adjunct, 10% barley malt mix and cold water.
What to do in this step: Add your adjunct (the flour, meal, grain of your choice) to the pot, 10% of your barley malt mix and simply add water until it becomes quite watery and pours like cream. You can test this by scooping some up and pouring it back into the pot. If there were noticeable lumps, add more water. Was it a smooth pour? Great!
Step 1 Details: We need to hydrate the adjunct mixture to the point that it absorbs all the water it can, while remaining liquid. This will allow both gelatinization of the grain, as well as enzymatic activity from the malt enzymes to occur in the following steps. Note: The amount of water is not important, only the consistency of the mix.

STEP 2: The “Dealing With the Stickiness” Step.


raise your cereal mash to the next rest and hold it.
What are we actually doing? We are heating the mixture to a certain point and leaving it there for 15 minutes.
What to do in this step: Turn on your burner / stove / heat source, and heat the “mini-mash” to 122°F or 50°C. Close your pot and wait 15 minutes. The rate at which you heat the mix is up to you; you can either heat slowly, stirring gently or heat quickly and stir like a madman…it’s up to you. After this step, you’ll notice that your mash doesn’t stick or clump at all anymore – clever, huh?
Step 2 Details: We are heating the mixture to a point where the peptidases in the malts become active (namely 45°C to 53°C for long chain proteins). Beta glucans are also reasonably active at this temp and help get your mixture to flow freely.

STEP 3: The “Squeeze Them Sugars” Step.


What we are actually doing? Heating the pot again to a certain point and leaving it there for 15 minutes.
What to do in this step: Turn on your burner / stove / heat source and heat the “mini-mash” to 149°F or 65°C. Close your pot and wait 15 minutes.
Step 3 Details: As there are starch particles suspended in solution that are able to be converted at this point, a saccharification rest converts them and assists in increasing efficiency in your overall mash procedure.

STEP 4: The “Final Boil” Step


What we are actually doing? We are boiling the mixture for 30 minutes.
What to do in this step: Turn on your burner / stove / heat source and boil the “mini-mash” for 30 minutes.
Step 4 Details: Irrespective of the specific grain you decide to use, boiling will gelatinize ALL of them. Gelatinization allows the alpha and beta amylase from the main mash to convert the newly gelatinized starches to sugars.

STEP 5: Combining Your Mashes


Combine the cereal mash with your regular single infusion mash and continue as normal
What we are actually doing? We are combining the separate mashes to perform the usual single infusion mash.
What to do in this step: At this point many books make references to keeping your main mash going and adding the boiling mix to your other mash to raise the temperature to the correct temperature – which is not all as easy as it’s cracked up to be for most hobby brewers. Here is the easy way:
  1. Calculate your temperatures for your single infusion mash as normal.
  2. Dough in your remaining malt into the main mash tun as per usual.
  3. Add cold water in little bits to your cereal mash pot until it is at the same temperature as your main mash.
  4. Dump in your cereal mash from the pot to your main mash tun.
  5. Go get another beer.
Step 5 Details: Many books will tell you to cereal mash in such a way, that it works almost like a decoction i.e. where you keep your main mash at a protein rest and then throw your boiling cereal mash in to get the entire mix to saccharification temperature. While that method is by far the most efficient, it also takes a lot of very good timing to get it right – not the kind of thing that would help most people get used to this kind of procedure. Instead, I have opted to keep all the processes simple and “single infusion” as possible, which simply means the only drawback of my procedure outlined here is that you would take an hour longer to brew – or as most would understand it, drinking 2 to 3 homebrews more than usual (hardly a reason for complaining). If you want some more info on how the cereal mash is calculated, please see the trailing section below on diastatic calculations…

Kruger Brewer’s Universal Cereal Mash Cream Ale recipe


This is a very easy recipe that you can use to get used to a cereal mash procedure. In addition, you can swap out the yellow corn meal and replace it with any other adjunct (unmalted grain) you like – a very good way to get to grips with the flavors of different adjunct ingredients!
OG: 1.050
FG: 1.010
IBU: 17
EBC: 8.1
ABV: 5.3%
Batch Size: 5 gallons (19 liters)
Estimated efficiency: 70%

INGREDIENTS:
  • 2kg (4.4 lbs) 6 Row malt
  • 1.5kg (3.3 lbs) Pale malt
  • 1kg (2.2 lbs) Yellow corn meal (or any other flour, meal, etc. you feel like)
  • 10g (0.35 oz) Falconer’s Flight hops ~ 60 min bittering addition – 13.5 IBU
  • 10g (0.35 oz) Liberty hops ~ 30 min flavoring addition – 4 IBU
  • 1 packet Safale US-05 yeast
MASH SCHEDULE:

Single Infusion at 149 °F or 65 °C for 75 minutes.
The amount of barley malt to remove in the recipe above for your cereal mash is 350g (about 12 oz) for Step 1. The first step in this recipe is to complete the cereal mash as outlined in the article above. Once you are finished with the cereal mash boil (Step 4), you can continue to prepare your main mash as you normally would. Next, mash in your grains and get to the required temperature in a single infusion scenario. While your main mash is in the mash tun at saccharification temperatures, cool your cereal mash to the same temperature – namely, 65 degrees Celsius or 149 degrees Fahrenheit - and simply add to your mash tun within the first 15 minutes of mashing. (Please see Step 5 for more info).
I sincerely hope that you will use the methods and information outlined above to your advantage and that you will use your newly acquired skills to make some truly amazing brews! Good luck!
Regards
Thean Leonard Kruger
(The Kruger Brewer)
 
Nicely simple explanation. I know a brewer who basically cereal mashes everything. I haven't yet found a need, but might start to experiment with different things this winter.
one thing I noticed is that you say to add cold water to the cereal mash to lower it's temp to that of the main mash. But adding this water would throw off your water calculations and mineral additions. They would have to be accounted for if you are going to be precise about them. Ice might be a better medium for cooling the cereal mash as it's the coldest thing the average person can get, and adds the least water. Also, an immersion chiller would do a good job of chilling it down without adding water.
 
I know you tried to simplify this, which is great. When you do your main mash, how do you calculate the water? Do you account for the 10% loss of the barley? How do you account for the unknown amount of water in the mini-mash?
 
Just keep track of your supplementary water additions to the cereal mash and subtract that from your sparge volume - then you don't have to worry about mineral additions etc (if they really matter anyways, as my recent experimentations informs me no one can taste any difference).
 
Great points made in comments above. That being said, major kudos on a very well-written and straightforward introduction to cereal mashing, especially to those of us who have yet to try it.
 
Hey Homercidal,
In reality, the amount of water you are adding would be so small as to make it insignificant. Even if someone were to go overboard, worst case scenario you would have a thin mash consistency - the only real drawback to that for homebrewers is that a thin mash cools quicker than a thicker mash. It would still convert your starches adequately, have negligible impact on mash chemistry and zero impact on the finished beer. Sure you could use ice, a wort chiller or even a glycol system, but like I said in practice, your brewing would be unaffected. The only time I would look closely at it is if I'm using something like 70% adjuncts, in which case mash salt additions is the least of your concerns. The above method works well even with as much as 50% adjuncts, irrespective of whether you're brewing at home or a 10 bbl commercial system.
 
Hey ericw,
Just calculate everything as you normally would in a standard single-infusion scenario. Don't account for any other changes in grain or water and you'll do fine. The reason you don't account for it is that it really won't make any difference. In terms of mash thickness, there is almost no difference between 2L / kg and 2.5L/ kg. There is only a serious difference between 2L/kg and 4L/kg and even then it's not a cause for concern. As an example, on my homebrew system, I would use 16 liters of water to mash in that recipe in a single infusion scenario, which corresponds to a mash thickness of 2.5 liters per kg. In my cereal mash, I accidentally am heavy handed with all the water I'm adding to the 1.3kg of malt in my cereal mash, leading me to add 5.5 liters more water than the single infusion would require (leaving the cereal mash to resemble a swimming pool, very unlikely unless I'm drinking Trappist-style homebrew while doing it). In this worst case scenario, I'm now saddled with a main mash that is 3.6 liters / kg - no worries at all. Absolutely nothing wrong with it. If you're paranoid it won't convert (which it will if you have diligently done your enzymatic calculations, which are the important ones), use an iodine test to make sure and give you peace of mind.
 
Very interesting and well written article.
Have a local bakery that gave me some rye grits left over form making light rye flour.
Would the process be the same? What adjustments would you make to the process or recipe?
I am looking at a rye pale ale with ~ 15-18% rye grits.
Thanks for this!
 
That's what I was looking for! Couldn't get my mind around where to subtract it from. But as mentioned, it might not really make too much difference anyway.
 
Well done! This article could well help some brewers expand their brewing horizons. As simple as you put it, even a rank amateur like me might give it a go. Enjoyed the article.
 
Couple of questions,
1, Do you have any recommendations for max % of total grainbill?
2, Whats the advantage? (flavour/body/cost/ etc)
 
I live in a country where corn meal is a staple food and I regularly add corn meal to my brews. Your first step to add as much water as to make a thin mash is something which I use although I can cook the meal to a stiff porrige no hassel. BUT your explaination that a thin mash will assist in gelatinizing makes sense and it is the first time I read it. Thanks!
 
I'd like to bump this question in terms of body. I would think that would vary based on the selected grain, but are there grains that would boost the body and mouthfeel to make this process worth doing?
 
The recipe above is good for up to 40% adjuncts. In terms of the rye grits / flour the process would be the identical, although you'll experience better efficiency from a finer grind. In terms of adjusting the recipe, simply swap out the corn meal and replace it with the rye adjunct. The corn meal in that recipe is around 20% of the total fermentables - at 18% you would be looking at about a bit less than 2 lbs of rye as opposed to 2.2 lbs. Let me know how it goes!
 
1. In terms of the maximum amount of adjuncts, you would be looking at a figure of 60% on a homebrew level without commercial amylase (enzyme). Any more won't work very well.
2. Flavor-wise, you will never get the same flavour for a witbier like Hoegaarden unless you use raw wheat flour. Malted grains vs raw cereal have completely different flavor profiles. It's a whole new world of flavours out there that you wouldn't have been able to get in your beer before. To prove the point, go down to a large grocery store to the section where they sell flour, meal, etc....you can use ALL of them and any combination of one or many to your beers.
As a general rule of thumb, adjuncts always make the body lighter though there are exceptions.
Cost wise......LOL! Why do you think all the big breweries do this? Take the cost of a bag of bread flour vs the cost at your LHBS per pound - the difference is most likely ridiculous.
 
As mentioned above, the efficiency of a cereal mash cannot be competed with, not by flaked or torrefied grains. Also, the flavour profile of beers like witbier, flaked grains cannot touch cereal mashed raw grains for flavour. Whereas flaked is good in a single infusion scenario, a bit more effort and you have a radically different end product by cereal mashing. Try it and you'll see.
 
The difference between cooking a porridge and cereal mashing is quite wide. Cereal mashing separates the tiny particles of starch, whereas making even a watery porridge wont work that well. do a side by side and you'll see. Also, cereal mashing almost completely negates the use of rice husks (should've mentioned that in the article lol), due to the fact that you're now adding a homogeneous liquid to the barley mash = no stuck sparge.
 
For calculations on diastatic power please follow the link below:
https://krugerbrewerblog.wordpress.com/2016/08/29/diastatic-calculation-formulae/
 
Outstanding! Thanks for answering the questions posted, the conversations drove home the benefits of a cereal mash.
 
Brewed the Rye ipa with the rye grits 5# for a 10 gal batch @18%.
No stuck sparge but it was slow. All in all it worked well and added about 1/2 hr to the brew day as I was able to run the cereal mash concurrent to heating the strike water.
Thanks for the article.
Another arrow in the quiver.....
jbrown57
 
As in any brewing endeavor, you need to dial in your setup properly when dealing with any new ingredient or process. On my homebrew system and most European-made commercial systems, I don't do anything different and it lauters fine. However, on a Chinese made commercial system, I find that I need to readjust the grind to be a little more coarse to get the flow where I want it. Play with it until you're happy. Would love to know your efficiency on this batch vs your normal efficiency.
 
@Kruger_Brewer - great article, clarifies a lot for me about cereal mashing. However..... as someone using a Picobrew Zymatic automated brewing system, I have a couple of questions.
1) If I understand correctly, the cereal mash is a mini mash creating wort that is added to the main mash, yes?
2) Because the Zymatic needs a minimum amount of water to operate, would it matter if my cereal mash is very thin? I am thinking of trying to cereal mash in the machine with the full amount of water, then replacing the cereal with the main batch of barley and starting the main mash. After the cereal mash I can always weigh the cereal wort and replenish any water lost in the cereal mash.
Stefan
 
Thean, thanks for great article!
It turned out, that I'll be brewing with a lot of oats soon, but I've already purchased them in flaked form.
Can I make benefit from cereal mash of flaked oats as well?
Cheers.
 
Hey Stefan - on to your questions:
1.) Yes correct. The cereal mash is a different process outside of your standard mash.
2.) I'm not sure that's such a great idea. Yes, a cereal mash is most often quite thin, but it's best to do it in a pot separately. Doing it in the way you are saying may have other complications. My advice? First do it the way said in the article and then, once you've got the hang of it, work out the odds and ins of the automatic system.
 
Sure! I've never tried it as I've never used that much oats, but I'm sure it'll work out better than just doing it the usual way - especially if you're looking at 20% or more oats. Give it a whirl! Let me know how it goes.
 
OK, here’s the story: I’ve mashed ca. 5kg of grains normally plus done cereal mash of 1,5kg of oats with some pils malt on the side.
The biggest issue was I have 5 litre pot for the oats and it was way too small to ‘maneuver’ the mash easily. Beside that, everything went as described and I’ve noticed a small efficiency progress.
However, sparge was stuck, but probably not a strange thing, considering this amount of oats.
Will I do cereal mash again? Of course, getting a proper volume pot at first.
Once again – thanks!
 
Thanks for the article! It was shared with the brew club I'm in, so I tried it. I have a bunch of 10 grain cereal that I'm not eating (ham and eggs are much more fun!) I ground it to almost flour and used your directions on my stove. I made it pretty thin and had a pot with a good thick bottom, so no issues with sticking as long as you stir alot. When I got to the boil part it had thickened so added a bit more water. Added to my regular mash as directed, hit temp using your technique. When it came to sparge, it almost stuck. Would some rice hulls help me out? Also, not sure what character this will add to my beer. The recipe is basically an American pale before deciding to add the cereal mash. Your technique worked great and was written well.
 
Hey stblackrock,
If you are seriously having an issue with lautering, do this:
- On step 2, drop the temperature to 48 degrees Celcius (118 degrees Fahrenheit) and hold it there for between 30 minutes to 45min. Its a lot longer, but it will degrade the beta-glucans to a point where they won't be much of an issue in lautering.
- If you are still having problems (I would imagine your grain would have a lot of proteins in it at this stage) you could use a combination of rice hulls, as well as a step mash with one 30 minunte rest at 48 degrees in your main mash before continuing on to saccharification and mash out.
Let me know how it goes!
 
Thank you. I am going to try this. Buying rye flour at the supermarket is much easier than ordering rye malt and paying shipping.
 
Wheat gelatinization starts at 52°C and no, for all cereals it's the same. Remember, we are only prepping the cereal for saccharification in your main mash. Don't worry too much about it. Wheat also gelatinizes a lot faster than other cereals and you can spot it quite easily...it turns grey from White.
 
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