Whenever I cook oatmeal (whether steel cut oats in a rice cooker or pan, or rolled oats in the microwave), it always overflows. How do you prevent this?

Do you just use a bigger container? Do you just take the pan off the heat or bowl off the microwave when it's about to overflow? I've also heard that if you put dried fruit or something like that along with the oatmeal while cooking, that helps prevent it from overflowing -- is this true?


23 Answers 23


A bigger container is definitely the 'instant' solution.

I've never hear of fruit preventing overflow. I'd guess the theory there is that it has something to do with the fruit interfering with the bubble to prevent them from forming...but I'd doubt it without A LOT of fruit.

Generally I've done two methods:

  • Reduce the power and increase the cooking time. Cut the power by 30% or so and increase the cooking time, this seems to prevent as much of a rapid boil and alleviates the problem.

  • Determine the time right before it starts to boil over, cut power off, cover it tightly and just let coast the rest of the way. This is particularly effective if you're cooking in a vessel with good thermal retention.

  • I have a cheap digital thermometer that I put into liquids. When it reaches 95ºC it'll beep. I have no idea at what temp the oat will overflow. Oct 22, 2011 at 21:50
  • @BaffledCook good call!
    – rfusca
    Oct 22, 2011 at 21:51
  • After not making oatmeal in the microwave for a considerable time — and after upgrading to a new higher-wattage microwave — I tried making some the way I always had previously: half power, cook twice-as-long, stir halfway; but the results were disastrous. Tried again in a steep-walled covered container…same mess. Although I was skeptical, after seeing the same advice over at Cook's Illustrated, simply switching from a 6- to a 9-inch diameter bowl worked perfectly (using the half-power technique).
    – martineau
    Dec 31, 2021 at 15:25

Simply add a handful of raisins and it will not boil over. Have no idea why but it works.

  • 2
    And here I had been putting the raisins in afterwards... not only did this work for me, but I was able to cook at 100% power in half the time and didn't have to buy a larger bowl!
    – Michael
    Oct 2, 2019 at 16:38
  • Most likely, the raisins break the surface tension created by the water+starch.
    – Joe M
    Nov 19, 2020 at 19:14
  • 1
    but then you have raisins in your oatmeal
    – njzk2
    Jan 4 at 21:53

Adequate room for expansion is important. For oatmeal I don't bother to do anything special, just know how long I can set the microwave for without getting a volcano in the bowl, and set it there, or watch it carefully (and shut it off) if going longer - it's only a couple of minutes. Portion size needs to be consistent so that time is consistent, or you need to know what time is "safe" for each portion size.

What I don't see in the current answers to this rather old question:

Steel cut oats were a trial for me via traditional direct heat methods - wanting stirring, prone to boilover, takes a long time that I don't want to spend stirring and pot-watching. They do expand a lot, so you need to measure quantity and allow for that in bowl size, and provide adequate water. But no stirring, no boilovers, no fuss and no problem if left on longer than needed (so long as the pot does not boil dry) when I steam them (in a bowl over boiling water in a lidded pot) rather than trying to direct-heat cook them in a pot or microwaving a bowl. Just get the pot simmering and come back in 15-20 minutes to cooked oats.

If you tend to cook oatmeal (rolled oats) a lot longer than I do, the steaming method might be worthwhile for that as well. I only bother with it for steel cut, since I don't cook rolled oats very long anyway.


I'm having the same issue. If I buy the instant, in the serving size packets, cook in microwave in a ceramic bowl using water as a liquid, it cooks at 1min 20sec with no boil over. If I cook steel cut oats, not instant, ceramic bowl with water in the microwave, it takes longer to cook and boils over. So I'm thinking it's about the temp your microwave is cooking at and for how long. The longer it cooks and the higher temp it cooks at, the more likely it boils over. Obviously a larger container would fix the problem but part of why we cook in the microwave is simplicity. If I have to get a larger bowl to cook it in, then transfer into a bowl to eat it out of, I may as well use the stove top...well, for steel cut oats that is, because you just about have to cook it for the same amount of time. Any glass or ceramic bowls I have are either cereal bowl size or the larger mixing type bowls. I don't really want to dirty up a big bowl like that to fix a bowl of oatmeal:/ I prefer not to cook things in plastic in the microwave so that limits my options. Maybe I'll try the cinnamon just to see if that works for some odd reason:)

OK I did an experiment and I don't know what it means really. The cinnamon didn't work for me. It wanted to boil over regardless. Rather than cleaning up another mess I stood there and watched it so I could pause each time it began to boil over....not that this is a convenient solution, it's just what I did. BUT! What I found out, which is odd to me, is that after I paused, let it drop back down, hit start til near boiling, hit pause til it dropped back down again and hit start etc.....doing this about 5 times....the oatmeal could then cook for several minutes on its own WITHOUT boiling over. That's confusing to a simple minded person such as myself:)

So I was able to continually cook the oatmeal for 3 min without having to pause it at all...AFTER I paused and started about 5 times. Does that make sense to anyone else? I tried to change the temp on my microwave and it tells me it's not available at this time lol. WHAT??

  • 4
    This may not be a well-written answer (all I did when I edited was paste the three posts together) but it does include a method that sort of works - starting and stopping, followed by higher heat. And given that microwaves have lower power levels that work by starting and stopping, it's not even a far-fetched answer.
    – Cascabel
    Sep 8, 2016 at 1:31

Simple. Put your bowl of oatmeal with liquid in the microwave on high (most likely 10), set for a couple minutes. Press start, WATCH YOUR OATMEAL. As it cooks watch for boil over. When/if bowl over begins (you can tell) stop the cooking, power down to the next level, probably 9. Start again. Repeat this till you notice there is no boil over. Doing this I discover that power level 9 is fine, no boil over, but I do have to cook longer. Instead of the 3 minutes the package recommends (1 cup oats, 1/2 cup water) I must now cook for 4 or 5 minutes, depending on how I want the consistency of the oatmeal. This process allows me to "set and forget it" cooking. I know it will not boil over and I can do other things while my oatmeal is cooking for 4-5 minutes, like start the coffee grains :) Good eating to you and all.


Since you didn't mention how you cook your oatmeal, I'll use the ways I've cooked mine as a reference for how to answer your question.

I usually cook old fashioned oats (lacking those I use quick oats) with brown sugar in milk, on the stovetop (but I used to do it in the microwave). I've done it in water before, but not enough to where I want to say much about it. I add a fair amount of milk, but I cook it until most of it's absorbed on the stovetop (I made it soupier when I cooked in the microwave).

In my observations, oatmeal will overflow if you cook it on high heat for too long.

For the stovetop, if you use a lower heat and cook it longer, or turn it down before too long, you shouldn't have particular problems (and you'll be less likely to burn your milk that way on the stovetop). On our stovetop, on one of the two larger burners (in a glass or stainless steel pot), it doesn't overflow if the heat is set on 4 (with the options being, from lowest to highest, these: low, 1, 2, 3, 4, 5, 6, 7, 8, 9, high; 5 is medium heat).

For microwave cooking, there's a sweet spot you just have to learn to find, and I don't remember what point that was. Stop cooking it before it overflows, and expect it to overflow if you cook it too long. (I didn't deal with temperature settings or anything; so, there are other microwave solutions, I'm sure).

FYI, I'm not recommending using a microwave for oatmeal (although it can taste pretty great). I personally think it's healthier to cook oats and other grains longer than the microwave allows palatably.

I have found that some substances can change the consistency of things like milk porridge. I'm not sure that fruit prevents boiling over, but it's possible. I know food grade diatomaceous earth seems to reduce curdling (like if you boil some jam in your oatmeal, the jam might cause it to curdle into acid cheese), anyway.

Edit: An even better option than the stovetop can be to bake your oatmeal. It just rises a bit, but it doesn't flow over or anything. The milk doesn't burn this way, either, and you don't have to stick around while it cooks. I'm not sure the ideal length of time to bake, but I cook it in a small glass or ceramic casserole-type pan on 450° F. in a toaster oven on the bake setting for less time than I expected. Keep a watch on it the first few times to get an idea of how long to cook it.


Bowl size is important. With milk or starchy products go for a wider bowl to stop overflowing

Generally ceramic or glass bowls work better than plastic, as they seem to absorb heat from the rising bubbles as slow them down

Add sugar after cooking, sugar will make for more sticky bubbles that will keep rising


I never have an issue with oatmeal boiling over when I put cinnamon in the oatmeal before cooking it (in the microwave). I use extra thick rolled oats. I set the microwave at 60% power for 4:30 minutes, but even so, if I forget the cinnamon it will boil over.


I see four factors at work here:

  1. Vessel size: Choose a pot or bowl with plenty of room for foam to expand without overflowing.
  2. Heat control: If you can keep the heat just below a full boil, it's much less likely to boil over. This is much easier to do on a stovetop than in a microwave.
  3. Ingredients: Boil overs happen when starch (from oats, pasta, etc.) or protein (from milk, eggs, etc.) get into the water and create a mixture capable of foaming. Minimizing these ingredients can help, but you don't want to reduce the oats in your oatmeal. Instead, you can add other ingredients that interrupt the foaming action. Some other answers suggest using dried fruit or cinnamon for this, but my favorite is a bit of fat such as olive oil or butter.
  4. Mechanics: Try laying a wooden spoon or a few wooden skewers across the top of the pan. This helps when boiling potatoes or pasta, so it should help with oatmeal, too.

Out of these four things, the first two (vessel size and heat control) are going to make the biggest difference. The other two can help, but don't guarantee success.


Wanted to add my $0.02 about cinnamon. Specifics: I use rolled oats and water in the microwave, 1/2:1 in various types of bowls, and have had the boil-over mess problem for years. I found that using the on and off routine once boil-over began did work, but is a bit of a PITA. One day I added my cinnamon (and I wanted to point out that I use a lot of cinnamon, sometimes with nutmeg and/or ginger, but in any case a lot, really a lot of spices, easily a tablespoon and perhaps more). And I add the spices before adding the water, don't know if it matters, but this technique works (for me), and in watching the boil process I see that the bubbling has changed in character completely. Instead of the violent bubbling (yes, volcano!) and expansion of the whole contents of the bowl, now it bubbles quite gently and does not expand all the contents of the bowl as was happening before (in a ceramic bowl and two differently shaped plastic bowls). Perhaps all the powder fills the interstices of the oats/water and keeps the bubbles small and fragile? I don't know and I don't care because now I can make my breakfast without a mess or the tedious on-off-wait-on-off-wait-etc.


Try heating your water to a boiling without the oats. Place the amount of oats you want to eat in a microwave safe bowl, then pour the water on the oats until all oats are in the water and cover them for about 3 to 5 minutes. You not only will have an easier time washing the pot and you won't have it bubble over.


The easiest solution for well cooked creamy oatmeal in the microwave that has worked for me is the following:

REDUCE MICROWAVE POWER! By 50%, or thereabout :)

I have yet to see a microwave that will not allow you to reduce power. The instructions on the oatmeal package say that it should be cooked on HIGH for about 2 1/2 - 3 minutes. Well, you all know how that goes - big mess :) So I started experimenting with shorter time until I found the sweet spot to be 1 min 30 sec. Now I cook my oatmeal with water, 2 to 1 ratio as it says on the package and when I cook it for 1 min 30 sec it comes out watery and needs to be left for several minutes to thicken. I don't know about anyone else but for me using the microwave is for convenience and if I have to jump through hoops like stopping,stirring, etc it defeats the purpose of the whole exercise. I want to be able to put water and oats in the bowl, put the bowl in the microwave and go make me a coffee and when I come back there is a perfect bowl in the microwave, pretty much the same as if you did it on the stove top sans stirring and tending to it. And I started experimenting again and was able to achieve that. I found out that my particular microwave would cook a bowl of oatmeal (1/2 cup oats and 1 cup water to be exact) in 2 1/2 minutes at 50% power. Oatmeal came oat perfect, thick and creamy but not mushy. So there it is, experiment with your particular oven as they all vary, but you should be able to get similar results.

I am talking here about Old Fashioned rolled oats, have not experimented yet with steel cut, but expect to be able to cook them well with even lower power and longer time. Just my $0.02


When using a rice cooker to cook steel cut oats, simply leave the lid open while cooking. I use the brown rice setting on my rice cooker. And never stir until it’s done. It’s perfect every time!


What liquid are you cooking your oatmeal in? I ask this because when i first started eating oatmeal i was using milk and the microwave and i was having the same exact problem. Recently, i started just cooking the oatmeal in water and haven't had that problem since. I use a flavored oatmeal (i recommend the Maple and Brown Sugar weight control from Hy-Vee!!!) and it tastes just as good to me whether i cook it with milk or water.

rfusca is right about the larger container being an instant solution. I also have a theory about the type of container you use. I'll spare the details but at first, i was using a plastic bowl, overflow like clockwork, i switched to a porcelain bowl since, no overflow. It seems to cook better in the porcelain also. Haven't tried glass yet.


The key is the amount of liquid. If you have a real preference for mushy oatmeal then cinnamon and power reductions (although the latter not alone I've found) can help, but only adding a little over 1/2 liquid works perfectly. For me it makes a perfect consistency for adding some milk after and never overflows. I have it almost daily.


Since I don't want to use a big bowl to cook a single portion of oatmeal, I find that I have to watch the oatmeal and stop the microwave and stir it every minute. I know that is a pain, since I want to put it in the microwave and then forget about it until my shower is over, but it is the only thing I've found that works.

I have read about slow cooker oats. You get the regular steel cut oats and let them slow cook overnight. I haven't tried it (because it also seems like a lot of work) but that could be a solution if the whole family eats oatmeal in the morning.


I run a cube of margarine or butter around the inside edge of the bowl before cooking. Not enough to add calories. Also have set 1 paper towel on the turntable to catch any boil over if I don't want to do the butter thing. Has anyone tried laying a wooden spoon over the bowl as you do for stovetop pasta, soup etc.


Success at last! I was determined to microwave oatmeal without an overflow mess, so after reading everything online I decided to start experimenting. My first one was a perfect success:

  1. Used a 3 cup (plus or minus) cheap ceramic bowl (family dollar or Walmart).

  2. 1/2 cup old fashioned oats : 1 cup water

  3. Microwave at 60% power for 3 minutes. (first time I've used the power control)

My oatmeal cooked perfectly, tasted great, not a hint of bubbling over (I watched it). Now I can teach my grandkids to cook oatmeal for themselves without worrying about them!


Just add some flaxseed. If you add a teaspoon to a tablespoon of flaxseed it has a nice nutty flavor plus more protein and it keeps your oatmeal from boiling over. You'll be pleasantly surprised


I am wondering if in some cases anyway, it's not something with the microwave. I say this because I have been making oatmeal in a bowl for years, the same way, and only for the past few months has it started to overflow, even at 80 percent power. I plan to start by giving the interior a thorough cleaning. Our machine is over ten years old, and the lights on the board have really faded anyway, so at the very least it might be a sign to shop for a new one.


Easy, place a wooden utensil across the top of the bowl. Don't know how I found this out, but it works. Haven't tried any other wooden utensils, although it may work with wooden chop sticks or the like. Enjoy!

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    This is already in another answer; please don't repeat answers.
    – user34961
    May 10, 2018 at 10:09

Lower the power setting or try defrost mode~~~ I had read somewhere to lower the power on your microwave but that button would not work on mine. So... my clever husband decided on a defrost setting :-) it's lower heat and definitely works. I decided on a meat setting and how many ounces I think is in the bowl. Play with your adjustments and settings and just keep an eye on it until you find your sweet spot.


It's surprisingly EASY!

As I explained in a blog post, it's very easy to get it well. It never boils over for me when I do it that way.

  1. Place oatmeal and 1/2 C water/milk in a bowl in microwave.
  2. Set your microwave to 2 minutes and then hit the ‘Power’ button. Choose 8 or 80% power.
  3. Then hit start and go deal with your screaming toddler/teen/puppy. When you think… oh crap! I forgot to watch the oatmeal so it doesn’t boil over… You’ll remember… oh yeah, it NEVER boils over anymore!
  • 1
    Hello Carissa, and welcome to Seasoned advice! We are glad that you chose to share your method with us, but the way you chose to do it annoyed our users, reflected in downvotes and spam flags. We never accept link-only answers, but require at least a summary of the linked information, so 1) users can judge the solution at a glance, and 2) our information doesn't degrade when links die. Also, we allow people to link to their own products or blogs when they contain a direct answer, but aggressive promotion, or insufficient explanation in the answer itself, is not allowed.
    – rumtscho
    Jan 3, 2015 at 11:42

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