Tomatoes in the Pressure Cooker

Tomatoes in the Pressure Cooker

Does your pressure cooker scorch and burn at the thought of pressure cooking a tomato-based recipe? Are you tired of chipping away last night’s dinner from the base of your pressure cooker?  Think you can’t pressure cook a recipe that is boiled, soaked, or stewed in tomatoes?!?!  I’m sharing my pro tips for getting delicious scorch-free tomato-based sauces and recipes in your pressure cooker.

First, let’s get a big pressure cooking myth out of the way…

It’s not the sugar

I’ve seen this myth perpetuated in cookbooks, websites and discussion boards: Pressure cooking tomato sauce scorches because of the sugars in the tomato.

It’s not true.

Here’s why:  sugar, once heated, is a liquid, and a liquid is not very thick, it will not sit at the bottom of the pressure cooker, it will boil. I’ve brought a pressure cooker to pressure with 50% sugar or honey on more than one occasion – see my lemon marmalade and old-fashioned strawberry jam recipes. These recipes don’t scorch.  Plus, the label on my jar of tomato puree (passata) says that it only contains 4.5% sugar which is a lot less than what is in those jam and marmalade recipes.

So let’s be clear, that it is not the sugar in the tomato sauce that melds your recipe to the base of the cooker into a jagged layer of carbon.

It’s the thickness

What is actually burning tomato-based recipes is the viscosity, or thickness, of the tomato liquid. Here’s a good explanation about what is technically happening.

Tomato sauce, which is considerably thicker than water, puts up more of a fight. Like ketchup, tomato sauce is a highly viscous substance, which is to say that it resists movement because there’s considerable amount of friction between its molecules. It’s also technically known as a plastic liquid. This means that a substantial amount of effort or force is required to make it flow, but once it starts moving, it does so quite easily. So when the liquid in tomato sauce reaches its boiling point, steam pressure builds up beneath the surface of the sauce. For a while, the sauce remains unmoved, but finally the pressure comes to a head and the sauce gives way, erupting to release the steam.

-(“Why Does Tomato Sauce Splatter Everywhere When It Cooks?”)

While the sauce remains “unmoved” it is actually sitting on the base of the pressure cooker, scorching. Each tomato product has its own viscosity. The thicker the tomato product the more liquid needs to be added to prevent the recipe from scorching. Here are the guidelines I came up with and follow when writing a tomato-based pressure cooker recipe.

Pressure Cooker Tomato Product Quick-reference

The items are listed in order of viscosity (thickness) along with my notes on how to use them. The more viscous an item, the more likely that it will rest in the base of the pressure cooker and scorch. Please note that "a cup" is equivalent to 250ml, 1/2 cup 125ml, and so on.
productconsistencyhip tips
prepared pasta saucecommercial pasta
sauce or salsa
very viscousThese products often contain thickeners and gels that will stop prevent the sauce from boiling. Add to the recipe after pressure cooking or follow a recipe that does not use these products. Otherwise, follow instructions for puree, below.
Tomato PAstetomato paste
or concentrate
very viscousDilute with ten to twelve times the amount of water to pressure cook by itself. That's about a cup of additional liquid per tablespoon used.
Tomato Pureetomato puree',
passata or
homemade sauce
viscousDilute with the same amount of liquid to pressure cook - that's one cup of additional liquid per cup of puree.
Crushed Tomatoescrushed tomatoes
(fresh or canned)
somewhat viscousDilute with two-thirds the amount of liquid to pressure cook - that's 2/3 cup of additional liquid per cup of crushed tomatoes.
Chopped Tomatoeschopped tomatoes
(fresh or canned)
not very viscousDilute with half the amount of liquid to pressure cook - that's 1/2 cup of additional liquid per cup of chopped tomatoes and their juice.
tomato_slicedquartered tomatoes
not very viscousMash fresh tomato wedges to release enough liquid for the pressure cooker to reach pressure.

Now, remember, the liquid added to tomato products can be water, stock, or wine or – it can be contributed by the other ingredients added to the sauce. For example, carrots and onions are about  88% water, a bell peppers 92% and ground meat is about 73%- so a pound (500g) of ground beef can contribute almost 1 1/2 cups (350ml) of liquid to a tomato-based sauce which can easily mitigate some of the scorch.  You don’t need to figure all of this out – I already make all of these calculations for you in the recipes on this website and my cookbook.

7 tips for perfecting tomato-based recipes

In addition to using the right balance of cooking liquid for each tomato products, here are a few more things to keep in mind:

DO Un-thick the Tomato Product – Follow our guidelines,  in the Pressure Cooker Tomato Product Quick-reference table above,  to figure out how much additional liquid your tomato product needs for the recipe.

DO Scrape it – Don’t build the groundwork for things to stick onto anything else that is already sticking.  Scrape the base of the pressure cooker well to lift-up onions, pasta, rice, etc.  A good time to do this is usually during a de-glaze step (where you add wine or stock) or just before closing.  My weapon of choice for this task is a flat-head bamboo spatula.

DON’T Puree – Don’t blend or puree’ ingredients before pressure cooking – or at least wait until after pressure cooking. Keeping most of the ingredients in large pieces keeps the sauce from getting thick before you’re finished pressure cooking.

DO Bring’em To A Boil – For iffy tomato-based recipes, bring all of the ingredients to a rolling boil before slapping on the pressure cooker lid. This ensures that everything in the cooker moving quickly enough to generate steam and, eventually, build pressure.

DO Layer Like Sass – Lorna Sass, the Queen of Pressure Cooking, introduced a novel way to keep thick tomato sauces from scorching in her cookbooks.  She layers recipe ingredients in the pressure cooker by the thickness (stock first, veggies after, tomato sauce last) and then directs the cook not to stir the pot before closing the lid to pressure cook (here’s an example).

DON’T Go Processed – Never use prepared “pasta” or “salsa” sauces as they usually contain starches, gums, flours and other thickeners which will prevent the cooker from reaching pressure. If that’s all you’ve got, mix it in after pressure cooking and simmer the flavor into the food.

DO Bain Marie It – One of our readers, shared in the forums that when there is no other option they use the pressure cooker bain marie  (aka pan in pot) method to keep their sauce from sticking.

What are your tips for avoiding scorches from tomato-based recipes?  Post them in the comments!

Tomato-based Pressure Cooker Recipes

Here are our no-fail tomato-based pressure cooker recipes that put all of this information and tips into action:

Now, you!

Let us know in the comments if there a particular tomato-based recipe that’s proved elusive or what you do to keep your tomato-based recipe from scorching.


Pressure Cook Tomato-based Sauces like a Pro!

Pressure Cook Tomato-based recipes - like a pro!

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  1. Interesting. I have never had tomato’s scorch and I tend to do a lot of tomato dishes. I’ve even used bottled BBQ sauce (did add other things to make it interesting and that did thin it a bit).

    Good to know it could be an issue.

    1. I’m impressed that you’ve never had a scorch! It took me a while to figure out all of these things especially using electric pressure cookers. Props to your cooking intuition.



      1. Maybe just luck, and I’m using the T-Fal stove top so heavy bottom, maybe that helps? That and I use your book a LOT. Tried a bunch of other books, even the generally trust worthy ATC (their PC cookbook is a disaster) and yours is by go to for the PC.

        1. Aha! Yes, high-quality stovetop pressure cookers have less of a scorching issue than cheap stovetops and practically any electric without a non-stick insert.

          Thanks for noticing the quality and care that I put into the hip book – it’s hard to get recognition in the flood of new books about the pressure cooker.

          Particularly disturbing (and depressing for me as a writer) is the flood of crappy e-books form made-up writers filled with recipes and photos copied from the web (including this website). Occasionally a reader points them out and I can ask amazon to take them down but it’s really getting out of hand.

          ATC has a team of chefs, a test kitchen and infinite number of pressure cookers but they only managed to convert slow cooker recipes to the pressure cooker badly – rather than innovate, simplify and improve on existing techniques. They lost a real opportunity, and at least one fan with their pressure cooking book. I was disappointed, too!



          1. Hmm, never thought about that drawback to the electric ones. Not a killer just a matter of “know your tools”.

            I do catsup fairly often. I don’t use that much but neighbors love it so it’s hard to keep in stock. And summer times I make up a lot of tomato sauce because tomatoes get very cheap at the farmers market. Sounds strange but Detroit has one of the largest farmers markets in the US. It’s just HUGE and especially late summer tomatoes and peppers are insanely cheap. And of course we have snow and usually very cold winters so it’s great to be able to pull out of the freezer then.

            My opposite of a PC kitchen toy is a Souse Vide circulator. Between the two life has transformed.

  2. Thank you, this was very timely and will help me be creative with my quickly ripening tomatoes.

    1. Stay tuned, as in a few weeks I hope to publish something will use-up 6 pounds of tomatoes all at once! ; )



  3. I gave up on all tomato products to the very reason you described. Will try with this in mind…thank you.

    1. I hope you will be tempted to try one of my tomato-based recipes. They are fully tested and use the methods in the article. ; )



      1. OK…been lookin’ at your Sloppy Joe’s!

  4. Tomato based Indian dishes like Chicken Tikka Masala are the type recipes where the IP gets overheated in my experience. Last time this happened, I scraped the bottom really well with a flat wooden spoon and added a cup of water. That did the trick, but I’ve gotten the overheat error more than once with different Indian dishes. These dishes typically have tomato purée, tomato paste, onions and yogurt.

    1. It depends on the recipe you use – I’ve seen different versions of Tikka Masala online and some include dairy or thickeners (before pressure cooking – the horror! ). I think the key is to find a good quality recipe for those dishes and work from there.



    2. Yogurt? If I even put grated parmesan cheese, like from the canister, in my IP, it gunks to the bottom. I cant imagine yogurt. I wudnt dare make mac n cheese in my IP and ppl do it alot tho.

  5. I made another Indian recipe in my IP. It was a Chicken Chickpea Masala. This one called for crushed tomatoes. Instead of stirring them in with the spinach as per the recipe I put them on top (broth,onions, spices on bottom, bone-in chicken breasts next, then spinach and homemade crushed tomatoes i.e. Pulsed in my Vitamix). I also added a slight bit more chicken broth. The recipe turned out great with no overheating/ sticking. I used the broth to help scrape up all bits of spices that tried to stick to the bottom. I probably could have left out the little bit extra broth as I ended up thickening it at the end with cornstarch. This recipe had a lot of comments about overheating and burning, but thanks to your great tips, that didn’t happen to me.

    1. Yaay, Wendy! BTW, you don’t need to increase the cooking liquid if you’re using the Sassy layering technique – but it sounds like you already figured that out. ; )



  6. Interesting. I have only had it go inti OVHOT once but no scorching. Still good to know and very timely as I just filled pot reasonably full with heirloom and plum tomatoes. Plus onions and tomatoes. Lasagna tomorrow :).

  7. I have twice scorched my food in my pressure cooker because I added the tomato product at the beginning.I will definitely try it your way next time.

  8. Question: If I plan on freezing my yellow pear tomatoes just to create chunked tomatoes (similar to diced tomatoes) to be used at a later time can these be done in a pressure cooker. Similar to doing your sauce recipe? I have used your recipe in doing sauce in a pressure cooker. Would I just quarter the tomatoes and mash them slightly with a potato masher? How long should I cook (simmer them)?

  9. If you do get food burned onto the pot, I have a weird, non-organic solution: Put a dryer sheet in your pot and cover it with hot water. Leave it for a while (even overnight). The burned on food will be totally released; no scraping, no scrubbing!

  10. Related OXY Clean will dissolve organic matter pretty quick. You can get the “OXY Free” version and it won’t have any added scent. Or if you are or know a home-brewer PBW (powdered Brewery Wash) is a bit more effective. One catch is that while this works great on stainless steel it can eat into aluminum.

  11. Thank you for this post!

    I was about to make my first IP chili and thought it best I consult something, good thing I read this first! Instead of adding my Tabasco chili starter in WITH the veggies and beans I pressure cooked those in a cup of water (cherry tomatoes balanced on the top layer!) and added the starter sauce afterwards! I feel as if I avoided a burnt mess!

    Loving your blog.

    1. Dhanya, I see from your previous comment that you’ve been pressure cooking up a storm!!! Great job – the chili looks great. Please consider stopping by our recipe swap forum and sharing the recipe!!



  12. I did my first tomato based recipe last night and got the BURN error. Resorted to doing pot in pot to finish it. I guess I will try the layering option one of these days.

    1. Don’t give up Corky, it takes a little practice to figure it out. If you follow the tips in this article it won’t happen again!



  13. Thanks for the guide, Laura! Tomato sauce have always scared me a little, because there is so much variation in thickness that I was never sure how much liquid to add. My homemade marinara has tomato paste, and I was afraid to use it in my Instant Pot until I read a recipe (I can’t recall whose it was, I hate that I’m not able to give her the credit) for spaghetti with marinara that also included tomato paste. It is added last and not stirred in until after cooking.

    It felt strange, leaving the tomato paste out as I was building my sauce, and seeing the big red blob sitting on top of the pasta was just bizarre. But it worked! My sauce had all the flavor I wanted, and letting it sit for a moment to steam off excess water thickened it so that I couldn’t tell the difference. It even showed a little Maillard reaction from exposure to the superheated steam as it cooked.

    1. Thanks for sharing this! I’ve been debating how to mske my spaghetti sauce in my IP. The article helped me work out liquid requirements, now I’ll add my paste like this.

  14. Dear Laura:

    I would like to can tomatoes this year–my garden came on very late, but I now have pounds of tomatoes! I want to just peel, chop and remove seeds (I don’t mind the skin,but can take it off if necessary). I would also like to make a sauce. Please advise as to how to bring the tomatoes up to the right temperature in order to can them–either chopped, or as a sauce (no veggies, or spice). Thank you.

  15. I read this article with interest because I cook tomato based meals every single day and have never experienced scorching. I didn’t know it was a thing. My base is Onion, carrot, celery, sometimes leek or fennel sweated for 10 minutes. Then I puree whole raw fresh tomatoes with olive oil, pepper and salt in a nutri bullet and tip it into the pressure cooker. I rinse the nutri bullet container with a bit of red or white wine. Then I throw meatballs or sausage and pasta or (fast soaked in the PC) beans into the pot and cook on low for 7 minutes. The meal is accompanied by sauteed spinach or cabbage. Voila, dinner, no sweat.
    I love your site and refer to it whenever I have a pressure cooker question. Thankyou for the great and reliable information.

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