Here’s an easy and delicious way to get rid of 6 pounds of tomatoes in one fell swoop – you’re going to be making LOTS of sauce.
Once I figured out how to reduce the time to evaporate the liquid of the tomatoes in the pressure cooker ketchup recipe, by keeping them mostly whole, I realized I could use this for tomato sauce, too. In fact, I had no choice, as my husband who can’t let a good deal slip by him, arrived at home with another 8k (16lb) box of ripe plum tomatoes.
Tripling the quantity of tomatoes, from two to six pounds while reducing liquids initially gave me a “scorched” sauce as the viscous tomato juice struggled to boil. So here, instead of closing the pressure cooker and going, we bring the contents to a boil before pressure cooking.
See Also: Pressure Cook Tomato-based Recipes like a pro!
Keep the skins and seeds, really..

Traditionally Italians peel and seed everything – including tomatoes for sauce. But my cooking style is very rustic, for the sake of ease. So, it was a lovely surprise to discover that just like there are benefits to leaving the skins on potatoes (protein) there are also benefits to consuming the skins and seeds in the tomatoes!
According to a study, a large portion of the tomato’s antioxidants (aka phenolics, flavonoids, lycopene and Vitamin C) happen to be in the tomato’s skin and seeds. In fact, more than half of the tomato’s nutrients are found in the pulp. So, according to science, using the whole tomato in recipes doubles this veggie’s nutritional punch.
Which setting to use to reduce..
If you have a stovetop pressure cooker, choosing the heat setting for reducing the cooking liquid (after pressure cooking) is easy – just turn the flame as low as it will go while ensuring the contents are still bubbling and boiling.
Electric pressure cookers all have different saute, brown, and reduction settings that all cook to different temperatures and times. I found that on the Instant Pot that the “Saute LESS” setting worked the best – however it times out at 30 minutes, so when you go to check and stir the tomatoes it’s time to start that setting, again. For the Breville Fast Slow Pro the setting that worked the best was “Saute LO” which will run for 40 minutes before needing to be re-set – the “Reduction” setting of the Breville only goes for 10 minutes and cannot be increased so I don’t recommend using it unless you want to re-set it six times. I just got a Fagor LUX, and have not had a chance to make this sauce in it, yet, but the “Simmer” setting should work here -it goes for 30 minutes at a time.
For electric pressure cookers without the brown or saute’ function, just choose any pressure program and use it with the lid open (be aware that these could timeout at 20 or 30 minutes – so be sure to check that the cooker is still in “heat-up” mode when you go swish everything around).
Use it plain or fancied-up
This basic sauce is pretty darn good on its own, but with a few additions, you can get completely different flavors and effects. Toss in grilled zucchini strips for a nice summer feel. Or, add tuna and capers for a one pot meal. Or, mix-in a cup of ricotta to turn this into a creamy “pink” sauce. Leave a comment, below, to let us know how you used or zazzed-up your large-batch tomato sauce!
Preserving the harvest..
Personally, my family goes through A LOT of tomato sauce so stacking these jars in the refrigerator is not a problem for us. However, if you want to keep the sauce for longer, let it cool and transfer to zip-lock bags and freeze. If you have a pressure canner, or a pressure cooker/canner, hot pack it and process it for the “pasta sauce (no meat)” pressure canning processing time appropriate for your jar size, canner type, and altitude.
Pressure Cooker | Accessories | Pr. Cook Time | Pr. Level | Open |
---|---|---|---|---|
6 L or larger | none | 5 min. + more | High(2) | Normal |
(per serving)
- Serves: about 4-5 pint (500ml) jars
- Serving size: ¼ cup
- Calories: 42.9
- TOTAL Fat: 2.1g
- TOTAL Carbs: 6.1g
- Sugar Carbs: 0.1g
- Sodium: 12mg
- Fiber Carbs: 1.5g
- Protein: 1g
- Cholesterol: 0.0mg

- 4 tablespoons olive oil
- 2-3 medium yellow onions, sliced into rings
- 2 large carrots, roughly chopped
- 1 celery stalk, roughly chopped
- 6 pounds (3k) plum tomatoes, quartered
- 6-8 fresh basil leaves
- potato masher
- immersion blender
- 6 - 1 pint (500ml) glass jars and lids, freshly dish-washed
- wide-mouth funnel (optional)
- To the heated pressure cooker add the olive oil and onion discs. Saute' them stirring occasionally until softened. Meanwhile, slice the tomatoes (stir the onions every 4-5 tomatoes).
- Push the onions aside and add carrots and celery, saute' for another 5 minutes- while you finish quartering the tomatoes.
- Add the tomatoes and mix well, scrape the bottom with a spatula to ensure that all of the onion is lifted off the base of the pressure cooker into the sauce.
- Using a potato masher, mash down the tomatoes to get their juice out and get them under the "max" line of the pressure cooker.
- Bring the contents of the pressure cooker to a boil (using saute' mode), uncovered. When the tomato liquid starts to spray and sputter up between the tomatoes...
- Close and lock the lid of the pressure cooker.
Electric pressure cookers: Cook for 5 minutes at high pressure.
Stovetop pressure cookers: Turn the heat up to high and when the cooker indicates it has reached high pressure, lower to the heat to maintain it and begin counting 5 minutes pressure cooking time. - When time is up, open the pressure cooker with the Normal release - release pressure through the valve.
- Mix the contents of the pressure cooker and let simmer uncovered on low flame (or the lowest boiling setting on the multi-cooker) for 1 hour or until the contents have about halved. For example, for the Breville Fast Slow Pro, the lowest boiling setting is the "Reduce Lo" setting, and for Instant Pot the lowest boiling setting is "Saute' Less"
- The cooker can be left unattended for the first 30 minutes - then it should be checked more frequently during the last 30 minutes to ensure none of the tomatoes are sticking.
- Puree the contents well using an immersion blender.
- Set-up the jars on a clean surface and place a single basil leaf in the base of each jar.
- Pour the tomato sauce into each jar and close tightly.
- REFRIGERATE: Let jars cool completely and then store in the refrigerator for 5-10 days.
FREEZE: Let the sauce cool completely in the covered pressure cooker and transfer into pint-size Ziploc bags (about two cups per bag plus a basil leaf).
PRESSURE CAN: Don't cool as the processing guidelines call for hot packing. Process following the "pasta sauce (no meat)" instructions from the USDA Pressure Canning guidelines using the appropriate processing time for your jar size, canner type, and altitude. Only use a pressure canner for preserving jars this way.


Plan on dicing or just crushing my yellow pear tomatoes that I have, I am wondering if I can use the pressure cooker to do them, if I am going to just freeze the as crushed or diced tomatoes? Or should I just crush and freeze, and do no simmering/cooking? I did use your recipe for making sauce. Turned out well.
Gary, I just cored and cut up the larger (better boy, Mr. Stripey & Cherokee Purple) tomatoes to be portions about the size of a quartered plum tomato (which I also used in the sauce). Worked well. Don’t go overboard to crush or dice, it will cook up in the pressure cooker and then you can follow the directions to cook without the pressure — then puree using a stick blender or regular blender. No need to do all that work — the cooking process and pureeing process will do it for you. Look at her directions again, I think you might have mis-understood. Cut (I cored my larger tomatoes), saute the onions, celery and carrots, then add the cut up tomatoes, wait till liquid spurts from the tomatoes (that means it’s boiling), then put the lid on the pressure cooker, set to meat-stew (which gives you high pressure) and time for five minutes. Release the pressure after the cooking time is over, then cook on low for about an hour, right in the pressure cooker with the lid off (or if you’re doing a couple batches, move the pressure cooked tomatoes to a large stock-pot).
Then if you’re going to freeze, cool that sauce down, put in freezer zipper bags or in whatever container you’ll be freezing your sauce in, and store in your freezer. For me, I pressure canned my sauce since I use my freezer for stuff that cannot be canned (ie, fresh meat I froze, etc).
Gary, you can absolutely follow the instructions here using only tomatoes and you can hot water-bath can them, too (see our discussion in the previous comments with links on how to do this safely). However, you might want to start by slicing them in the size you eventually want them because all the crushing in the world is not going to change the size of the skins of the quartered tomatoes (except pureeing, of course). My understanding is that you “chunks” and not a puree.
The freezer already does some of the work to “break down” tomatoes (via growing ice crystals that pierce the tomato flesh) so if you’ve been happy with the results you’ve gotten from doing this in the past – there is no need to change this now. ; )
Ciao,
L
I have never made my own tomato sauce and am dying to.. and have these:
Ball Jar Wide Mouth Pint and Half Jars with lids and bands…
So how do I safely store the sauce exactly? Do I pour them into the jars and let cool before storing them in the fridge/freezer or can they just be put away when hot??
Thank you for this recipe!!!
Grace, let the jars cool and refrigerate. Never freeze a liquid in a glass container as the liquid will expand while freezing and shatter the glass.
Ciao,
L
I freeze in glass and the jars don’t break. The trick is to leave space for expansion and leave the lids off until frozen, usually overnight. You can reuse store bought sauce jars this way as well.
Actually the pint and a half jars I own are freezer safe jars. The freezer safe jars also include many of the jam jars. If it is a straight wall going all the way up they are generally freezer safe and will usually say so on the packaging. I use the freezer safe glass jam jars for making my freezer jam. Anything with a neck will not be freezer safe even if you leave room for expansion. I have tried it and know from experience. I have found cracked jars in my freezer and those that did not turned into cracked jars when they were dethawing on my counter or in my refrigerator. Only a few survived and it was not worth the waste and extra work of cleaning up to leave it to chance again.
We have different experiences then. I routinely freeze in glass jars that are reused from purchased items at the store and have never had one break when I’ve left the lid off until the contents are frozen. They’ve never broken when thawing in the fridge either.
Athena and Di, your discussion has been soooo educational for me. 1. I didn’t know freezer-safe jars even *existed*, and 2. I never thought of freezing a jar with the lid off. 8)
Thanks for sharing your experiences and tips!
Ciao,
L
I have also used glass jars to freeze, I was thinking of buying the wide mouth mason jars that are freezer safe and experimented first re purposing the store bought sauce jars with success. I wait for it to cool down completely and let at least overnight without the lid, so far no cracks (have been doing for about a year now). Didn’t buy the mason jars yet :-)
Laura thanks for all the great recipes, I had never heard of instant pot before I searched for a good slow cooker online (yes, that how I first heard about it). Love your yogurt recipe (no longer make it because I’m going dairy free, but its foolproof and delicious, the tomato sauce has been shared over and over and the ketchup one took me away from Heinz, the taste is not 100% the same but its close enough for me to abandon it).
Wide mouth jars are for this.
When I want to freeze liquids…I love my seal a meal / Food Saver machine. I place my sauce into the seal a meal bag, supported by anything that will keep it upright. When liquids are frozen. I then seal the bag..walla…keeps a very long time very fresh in my freezer.
Grace…I have given up freezing liquids in glass. Mason and Ball jars are freezer safe if done correctly. I love water bath and pressure canning and do them on a regular basis.
It saves so much more room to freeze in freezer bags. And who wants all those glass jars in their freezer anyway..not me! Or even better yet a Meal Saver with the bags is fantastic..can’t say enough how fresh and long items stay frozen.
Just place your cooled liquid to be frozen into a supported upright position using your freezer bags of choice and wait till it’s frozen and then seal it.
Can you make a half batch with 3 pounds of tomatoes following the same instructions?
Yes, as long as you can squeeze enough juice out of them in the “mashing” step for the cooker to reach pressure. If you can’t just add water, and then evaporate it away in the reduction step. ; )
Have Fun!
L
Is a normal release the natural pressure release (NPR) or quick release (QR). Sorry, newbie here and I really want to do this right.
Laura uses “Normal” where others use “quick”: Push the button, turn the knob or whatever you need to do to release pressure quickly and safely.
She uses “Natural”. for go have a cuppa and a lie down while you wait.
She also uses a couple of other terms too:
“Slow normal” release pressure slowly if your machine can do it. Or in bursts if it can’t
“10 min natural”. Have a cuppa but release pressure after that instead of having a lie down.
She advises AGAINST unnatural methods like pouring cold water over the PC as they pose an unacceptable safety risk.
I find that a nice simmer in the Instant Pot can be maintained for long periods by using the Slow Cooker setting with the top off, or off and on as you need. The strength of the simmer can be controlled with the Adjust control.
That works for smaller batches, what I did was about 6 batches and transferred each batch to my large restaurant-sized stockpot, added herbs and spices, Then I puree’d the contents of the stockpot and poured into pint size jars, and pressure canned. This has made a great quick spaghetti and pizza sauce!
That’s a helpful tip, thx
Oh, word. One more reason to love the Instant Pot. My house is redolent with the aromas of tomatoes, onions, and olive oil. My batch yielded 11 cups of rich, delicious sauce. I added 2 tsps. kosher salt and 1 tsp sugar, but that’s all the doctoring it needed.
My tomatoes haven’t fared well this year, so I had to supplement with a few pounds from the farmers market. Thanks for this awesome recipe!
Oh, Kim your sauce looks beautiful. Thank you for sharing a pic with us. I’m so glad to read that you’re happy with the results. Another weekend, another batch? ; )
Ciao,
L
Any reason why no garlic? Thanks for this though! Prepping 25 lbs of Roma tomatoes!!
No, there is no reason – you can apply this technique to your favorite sauce recipe. HOWEVER, garlic does lose flavor under pressure so I recommend keeping the cloves whole when browning and then removing them for the pressure cooking step and tossing them back in for the reduction step.
Have fun, send pictures!
Ciao,
L
Hi, So first let me say – YUM! This is my first year with my pressure canner/cooker and I think this recipe will be used a lot in the future. I’m trying to make the most of my new kitchen gadget, and I want to can this sauce. Having mostly experience with water bath canning, I’m used to the lemon juice addition. Am I right that when pressure canning the lemon juice is not needed to be safely canned? Sincerely an overly cautious newbie!
I too would like to know whether lemon juice is needed for pressure-canned sauce. I have a giant Mirro canner that I use for canning all sorts of things, including my tomato sauce. It’s so much easier and faster than using a boiling water bath. But it seems to me that at 10 lbs pressure (the level recommended by most recipes for canning), any pathogens should be killed off. If I don’t need to add lemon juice to other low-acid foods when pressure canning, why would I need to add it to moderate-high acid foods like tomatoes? Even the USDA recommends continuing to add lemon juice, but doesn’t say why.
Hi Erin and Alan,
I can’t tell you the “why” lemon is required but I looked at the USDA’s “Complete Guide To Home Canning”, and I noticed that only straight-tomato products (juice, whole, crushed) require lemon, while their “Spaghetti Sauce (No Meat)” does not.
Here’s a link directly to theit Tomato Booklet:
http://nchfp.uga.edu/publications/usda/GUIDE03_HomeCan_rev0715.pdf
I know that for hot water bath canning (and also in Europe) lemon and citric acid is recommended for ensuring the acidity of the end product is high enough to kill bacteria – but I don’t fully understand its role in pressure canning. It might be related to color retention – as one is OK with a brown sauce, but maybe not brown whole tomatoes.
Ciao,
L
I had a family member tell me it was for color retention so I quit using the lemon juice and only sometimes use salt when I use my pressure canner and I haven’t had any problems. However I generally follow instructions exactly when water bath canning since I know it has to do with getting the right pH necessary.
Allan Risk ….. Pressure Canned no need to add lemon. It’s for water bath canning. Some tomato are just to iffy and may have low acid count for water bath canning..it’s kind of a toss up between being a fruit and a veggie..Pressure canning is my preferred way of canning tomatoes. I don’t like the added lemon taste in tomatoes that are water bath canned. Just make sure you reach the right pressure level and time for tomato pressure canning. Adjust to your altitude.
Made this to.day, went very well. I think I will omit the carrots next time. There was a bit of sweetness in this sauce. I think it is from the carrots. Thank you for the recipe.
I made this sauce without the celery. I added I pound of pork riblets after pureeing the sauce and cooked them until they fell apart. It was as though my mama was smiling over my shoulder! The pork added a vast amount of flavor. I removed the bones and froze the sauce as directed in zip type freezer bags, with a small amount of pork in each portion. And now three months later I am re-living that day as I have throughly enjoyed my pasta with that wonderful sauce for dinner. Laura, you are a goddess! Thank you for showing me the pressure cooking path!
K7, so glad to hear you made this recipe your own – and what a nice addition, too!
Ciao,
L
I made this tonight – I’m new to my FAGOR LUX pressure / slow cooker and excited to work with it. I followed the recipe and things went swimmingly until I got to the simmer step. I used the “simmer” button on the cooker and after 1.5 hours, the liquid had not reduced enough. I decided to use the “Saute” button and that did the trick. The simmer just never got it hot enough with the top off. I assume that if I had opted to slow cook with top on, overnight, the water would not have evaporated. It looks good but I haven’t tasted it yet.
So, how was it?!?
Ciao,
L
Good! I froze much of it in separate plastic baggies so we’ll eat it over time.
Hi,
I’m a total newbie here. I understand that you can’t electric pressure cook low acid foods. However, can I use my new electric Fagor as a replacement for a hot water bath to seal my tomato sauce in the jars? Sometimes I only have a few jars and don’t want to boil a huge pot of water.
Thanks!
It depends on the size of your cooker – there is some new information about using steam to can vs. boiling water canning and this would be more convenient to do with an electric but I have not investigated it enough to recommend it.
I have tried to traditionally boiling-water-can jars submerged in water and then boiling using “saute” in an electric cooker – it was a tight fit because to cover the jars on a rack with water I had to fill the water beyond the max line and keep the lid closed hoping it wouldn’t splatter everywhere!!
Sorry, not helpful. But at least now you know what NOT to do!!
Ciao,
L
I just have to say…Are you kidding me? These will actually last in the refrigerator for 3 months? How is that possible? I realize that we Americans are crazy stupid about food safety and Europeans and Asians are much more realistic but even with my somewhat relaxed standards 3 months seems excessive.
Apologies, you are right. I’m not sure where that came from – as I’m usually careful about these things. I have updated the refrigeration recommendation in the recipe to 7-10 days until I can find the original source of my 3-month recommendation.
Thanks and welcome!
Ciao,
L
Hi Laura. I want to make this sauce! I am leery of putting in the Roma tomatoes with the skin and seeds in it. It doesn’t make the sauce bitter? Do the seeds make the sauce crunchy? Thank you!!
I would like to use your method of tomato sauce to make a favorite of my family’s spaghetti sauce that I usually make from 48oz cans of crushed tomatoes. I’m guessing that I would saute fresh onions and garlic first like you do with your fresh ingredients and then add the rest of the ingredients after using the immersion blender. Would that be correct? Going off the top of my head the other ingredients would be dry basil and oregano, salt, sugar, and wine or vodka. Not sure if that is correct because usually you would want to simmer it a bit to get the flavor of the other ingredients. Also would you know about how many 48oz cans your 6 pounds of tomatoes make? I want to make sure I’m putting in the right amount of the other ingredients.
You would puree everything at the very end – this keeps the sauce thin enough to keep bubbling without sticking or stirring.
Ciao,
L
I’ve made this sauce 3 times now with excellent results each time. I usually vary the amount of each ingredient based on how much I have. Will be saving to keep making again and again. Thanks!
Good morning! Our first batch is simmering now. What a great recipe. So far it tastes delish. We added some fresh basil, oregano and thyme from our garden. We also roasted some fennel seeds and added 2 bay leaves and 1 1/2 T. Sugar. We have a keeper here. Thank you for the recipe! Paul and Jaci from Missouri.
This is amazing with the addition of red wine, you don’t need to crush the tomatoes and the wine reduces along with everything else. I prefer a full body red, but I have tried it with white too. The latter creates a delicate flavor.
Go for it, Jill! Let us know how it turns out for you. However, keep in mind that crushing the tomatoes is done not only to extract juice but to save space. As you can see from the photos and videos six pounds of roughly-chopped tomatoes nearly fills a 6L cooker. Crushing the tomatoes lowers the contents to 2/3 full.
Ciao,
L
Love making fresh Pasta sauce now with your guidance! Wonderful, I now have 3 instant pots…LOL
My newest and largest 8qt. Duo…
Please tell me can I double your recipe in the 8/Duo pot? I finally convinced my daughter to pressure cooking and her hubby loves making fresh tomatoe sauce. Large family gatherings..so he will want to double the amount in their new Duo 8 qt.
In fact they bought 2…one for vacation ranch…lol
Thank You
Sylviah, you should be able to make 1 1/2 times the recipe in the 8L. How exciting to hear that your pots have become indispensable!!
Ciao,
L
A wonderfully informative post, as always. I was particularly happy to read about the nutritional benefits of *not* peeling the skin off the tomato. I never peeled tomatoes basically out of laziness and had always felt slightly guilty about it, but now I can feel virtuous!
This year’s backyard tomato harvest has been spectacular! I’m eager to try this sauce in my Instant Pot. I usually slow roast my cut tomatoes drizzled with EVOO, salt and pepper. Result is a wonderful purée after using food mill. I appreciate your advice about keeping skin and seeds!
I also have success freezing tomatoes and sauce in Mason glassjars. Thanks for your great tips and recipes.
Hi all-I’ve got a Fagor Lux and just made my second batch of this. I don’t remember how I did it the last time, but this time, the last step of reduction had to be modified from the instructions. The first half hour, I tried the “SIMMER” setting and it was just too low. I noticed that after the 1/2 hour was over there had been very little reduction and the sauce was still very watery. I then tried to “BROWN” setting and after 12 minutes, decided to go down to “SAUTE” for another 30 which I think was just right. I’m letting it cool now a bit and then will puree it. House smells heavenly!
OMG! Here it is the middle of October in Montana and SUDDENLY we have tomatoes, all of the different varieties have put forth amazingly. I do not have a pressure canner, but I do need to get these bottled up somehow and very quickly.
Question:
1. To just make a sauce without any additions, is it necessary to boil first? If so, for how long?
2. Can I do the entire cooking process in my Instant Pot–how long under what pressure?
Thank you,
I live somewhere that canned tomato sauce is not available. I have a recipe I have been using for years but I decided to try this one instead. This will be my new go-to recipe for tomato sauce. It produces a better texture than my old recipe, which also used whole tomatoes.
Hi, Laura, I’m trying to register but having trouble doing so. I get messages about using illegal characters. I don’t understand. Please help. Thanks.