Canning 101: Why You Can’t Can Your Family’s Tomato Sauce

full jar

Tomorrow is the first day of September, and with it comes all those traditional end-of-summer events, including tomato canning season (at least here in the mid-Atlantic where I live). Because the yearly tomato glut is finally beginning to arrive, I’ve been getting a number of questions about how to safely can tomatoes.

The most frequent question I get is from people wondering if they can boiling water bath process their favorite spaghetti sauce recipe. You know, the kind that has plenty of garlic, onions, basil, olive oil and sometimes even a few peppers.

Sadly, I always end up delivering disappointing news. You really can’t just can your family recipe. Anything canned in a boiling water bath needs to be high acid (for the science minded types, this means that it has to have a pH of 4.5 or below). This is because botulism cannot grow in high acid environments. However, tomatoes are in the grey zone, typically having a pH right around 4.5. Because of this, tomatoes need to be acidified when canned, so that the acid levels are pushed into the safe zone and the pH becomes something lower than 4.5. That’s why my instructions (and all other good ones you’ll find) for canning whole tomatoes includes two tablespoons of bottled lemon juice per jar (you can also use citric acid if you prefer).

When you make spaghetti sauce, one typically adds a slew of ingredients that, while delicious, lower the acid to seriously unsafe levels. Unless your family spaghetti sauce recipe contains several cups of red wine vinegar, it will be too low in acid to be canned in a boiling water bath.

Most canning information will repeatedly remind you that it’s incredibly important to follow tested recipes. While I will occasionally play around a bit with jams and pickles (and I only do this because I know which aspects can’t be monkeyed with), even I never deviate when it comes to acidifying my tomatoes. I always follow the instructions in either the Ball Blue Book or So Easy to Preserve when I want to preserve tomato sauce, soup and salsas.

The one caveat I have to offer is that if you have a pressure canner, you may be able to preserve your beloved sauce recipe (just so you know, any recipe that includes meat MUST be pressure canned). Pressure canners raise the internal temperature of your jars to temperatures in the neighborhood of 240 degrees, which is high enough to kill off any botulism spores that may exist in your food. However, you should still consult recipes that have been tested using a pressure canner to determine processing time and pressure.

The good news here is that there are plenty of safe, tested tomato recipes that are designed for canning. Let’s hear about your favorites!

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428 Responses to Canning 101: Why You Can’t Can Your Family’s Tomato Sauce

  1. 201
    Eileen says:

    pH test?
    IF the issue with water bath canning tomatoe sauce is the pH can we test the pH and add enough citric acid to get the pH <4.5 and then use the water bath. I know you keep saying meat sauces need to be pressure canned, but I can't figure out why if you can get the pH of the sauce <4.5, or when you add the meat is there more than just the pH issue?

    • 201.1
      Teresa says:

      From what I understand, in regards to meat, it’s the fat content, not the ph level.

      • Edwin says:

        From what I understand,the fat in the meat can protect spores. At least partly this would be because they exclude water (hydrophobic) and thus wouldn’t be affected by the pH unless it was far more acidic than you’ll get with citirc acid. (btw, this water exclusion is essentially the reason why microwaving meat won’t protect you either).

  2. 202

    […] with boiling-water canning, especially when they’re not even measured amounts (see this article for more information). I know that many people have canned this way for years, but in my opinion, […]

    • 202.1
      Jamie Ellis says:

      My great grandmother water bath canned all her stuff she didn’t have a pressure cooker and we ate everything she made. So I got her recipes and I follow them to the letter I have never had anything go bad or make anyone sick.

      • Marisa says:

        Food science has come a long way since your grandmother’s time. I would suggest updating your practices.

        • jill says:

          Also our food is different than your grandmothers. Her tomatoes were more acidic.

          • Kathleen Daugherty says:

            I have canned for over 30 years some food from my garden and from farms. It is harder in Nevada, but I still can. If you are serious you need to have a water bath canner and a pressure cooker. I got mine at Amazon for about $85.00. Your major expenses are the canner, pressure cooker and the jars. All of them are reusable with the exception of the seals. You know what is in your food because you made it. It doesn’t have excessive salt, sugar, and preservatives. I make a Large batch of sauce and pressure cook 7 quarts at a time. Kathleen

            • Jodi says:

              A pressure cooker should not be used for canning. Think you mean a pressure canner. There are pressure cooker-canners available also, but a pressure cooker alone is not made for canning.

              • mr smith says:

                I happen to have both cooker and canner and use both, but I found it depends what you are canning. Meat products only use the canner. If I’m canning a few pints of something like my plums or peaches Im not afraid to use the cooker, never had a problem. most people use canners or cookers know how to use them but dont really understand them.
                So I agree with you…do whats right, follow instructions. safety first

      • cheryl pezzuti says:

        I agree Jamie.

  3. 203
    Joan Polignone says:


    I would like to pressure can homemade sauce no meat and no garlic and the ingredients I use are:

    2 cans Pastene crushed tomatoes
    1 can Puree
    3 small cans of Paste
    1 Medium chopped onion
    1/2 cup of oil
    salt & pepper

    cook approximately four hours adding water occasional …….

    I need to know now if I can pressure cook this safely?


    Joan Polignone

    • 203.1
      Marisa says:

      Joan, I just can’t answer these kinds of questions. I’d suggest you look at the information about canning spaghetti sauce on the National Center for Home Food Preservation.

    • 203.2
      Carolyn says:


      I would suggest that you contact your County Extension office for research-based information regarding this topic. They will be able to provide you with scientific, research based information so you can preserve food safely.

    • 203.3
      crystal Petersen says:

      I would not suggest doing so because of the olive oil. You can put it in jars or plastic( I would personally use jars Mayo or miracle whip plastic jars or any similar jars or canning jars) and freeze it.

  4. 204
    John says:

    Hi Marisa. Going back to Eileen’s question from September, could you just add citric acid to your favorite sauce and measure the PH level until you get below 4.5 and then can in a water bath? Thanks so much.

    • 204.1
      Marisa says:

      It’s not a recommended technique, but if you were willing to live a bit dangerously, you could. You’d probably want it to measure closer to 4.2 or 4.3, just to give yourself a slightly larger margin of error. And if the sauce contained meat, it would not be advised, no matter how low a pH you were able to achieve in the surround sauce.

  5. 205
    Andy says:

    Too bad when the family recipe originated from Italy a couple hundred years ago…adding a bunch of red wine, citrus or lemon juice is not desirable.
    Does the pH requirement stay the same even if you add meat? And I assume the added meat would also lower the acidic value so you’d have to make even more adjustments to get that back up to 4.5. Am I correct?

    • 205.1
      Marisa says:

      It is not advised to process sauce containing any kind of meat in a boiling water bath canner. For that, you MUST use a pressure canner.

      • Barbara says:

        I just processed sauce and meat in a boiling water bath canner not knowing this should not be done this way, can I reopen the jars to correct this error. I just made 30 jars of plain sauce and 30 jars of sauce with meatballs, the meatballs were cooked in the sauce before processing OMG they are Christmas gifts. Please help

        • Marisa says:

          Unless you have a pressure canner, everything needs to go into the refrigerator as soon as it is cool. There’s no way to make low acid sauces shelf stable without a pressure canner.

  6. 206
    Hat says:

    There are two wonderful tomato pasta sauce recipes created with canning in mind in the better homes and gardens’ canning magazine from this summer. Both require the tablespoon per pint of lemon, and are a bit on the tart side, but have some lovely flavors of basil and roasted garlic, and are just waiting for added cheese or meat when heated and served. I sure hope they were tested because I have 30 or more pints heading out the door this Christmas!

  7. 207
    Kimberly says:

    So not for canning, but What about for short term storage? 2-3 days. And for freezing.

  8. 208
    crystal says:

    My husband cans his sauce and it turns out fine. But of course he makes huge batches, uses red wine and cooks it for what seems to be forever! I can’t say what his secret is because I’m not allowed in the kitchen, and I’m not allowed to touch the sauce…That’s what I get for marrying an Italian.

  9. 209
    Alexander says:

    Hi, and Greetings from Germany. I know, it is not directly topic, but as meat was mentioned several times, I would like to add that they are really a lot of different sausages and meat stew recipies around here that are usually canned during home slaughtering at approx 72 °C (160 °F), this being done as long as my gramma can recall. As far as I know, there are no Botulism problems with that, but of course nobody would eat something that was visibly under pressure when opened, or the content of a bloated tin can. Sorry if I missed the subject completely – Alex

    • 209.1
      Marisa says:

      There is actually a great deal of trouble with that. Meat is low in acid and botulism spores require temperatures of 240F to be killed. There is no safe way to process meat in jars without a pressure canner.

  10. 210
    Nikki says:

    Hi I am just wondering whether once the batch of sauce (does contain lots of white wine vinegar, tomatoes and has been preserved properly) has been refridgerated can it then be stored elsewhere or does it need to be pressure canned/heat treated again/ remain in the fridge or freezer until consumed?
    I wasnt sure at the time of making it and didnt want it to spoil so i put it into the jars and into the fridge, its keeping well but it would be better to have my fridge space back!
    Any hints you may have are greatly appreciated, even for next time i will remember to just heat treat and then store not in the fridge perhaps.
    Thanks in advance 🙂

    • 210.1
      Marisa says:

      You made the sauce, canned it, and then refrigerated it? If the sauce was high enough in acid for boiling water bath processing, and the jars sealed properly, there’s no reason why you can’t take the jars out of the fridge and put them in the pantry. More information about canning tomatoes can be found here:

  11. 211
    Stephanie says:

    I have a similar issue. I make a lot of sauces that I’d like to make in larger quantities and can for my big family. (Alfredo sauces, vegetable sauces, Asian brown sugar and soy sauce sauces, etc). Csn I water bath can these, or pressure can them? How long would I need to?

  12. 212
    CrabbeNebulae says:

    It’s simpler and tastier to just make a nice thick tomato sauce (tomatoes only) and add one generous tablespoon of lemon juice to each quart jar and water bath can it. Then, make your spaghetti sauce from that, fresh, when you need it. Tastes much better. Water bath canning spaghetti or pasta sauce, or any other sauce using tomatoes WITH A MULTITUDE OF OTHER INGREDIENTS, and trying to manipulate the Ph is not safe. Pressure canning spaghetti or pasta sauce, or any other sauce using tomatoes WITH A MULTITUDE OF OTHER INGREDIENTS, while safe, changes the flavor. I’ve found it best to simply make plain tomato sauce and use that in the family recipe when you need it instead of trying to can the family recipe. Keep it simple people, and keep your awesome family recipes intact and awesome.

    • 212.1
      Marisa says:

      You actually need two tablespoons of lemon juice per quart of product.

      • CrabbeNebulae says:

        You are right… my bad. I say “generous” tablespoon because I slosh it over a lot. But, two measured tablespoons is correct. Sorry.

  13. 213
    Lindsey Bosma says:

    Hi, I have been canning for several years and every summer I make a tomato basil sauce from the Blue Ball Book. This year in just one of my batches the oil separated after the hot water bath. (The recipe calls for one TBS of olive oil.) It is possible I used a generous TBS of olive oil, but otherwise I am not sure why this happened. I was wondering if you had any insight and most of all, is this safe?

  14. 214
    Joanne says:

    My Roma plants are beginning to ripen, I am really trying to get them ripe on the vine,but I have been freezing then to make sauce later. I am asking if slightly under ripped is OK to use to can. Could I still use table ripened like vine ripe? I plan to pressure can? People are saying it’s fine if the fruit looks good. l

  15. 215
    Jen says:

    Can you re-jar pasta sauce that is store bought? I’ve been trying to find information on this with no luck. I always end up wasting store bought pasta sauce because it doesn’t get eaten before going bad. I’m wondering if I can buy a large jar and then re-jar into the smaller ones.

    This is for times when I don’t just make my own sauce 🙂

    • 215.1
      Marisa says:

      It’s really not recommended that you recan store bought sauce. If you have sauce that you can’t use up fast enough, it’s better to freeze it.

    • 215.2
      wendy says:

      I have done this for years. I’ve used freezer bags or canning jars ,smaller amounts I use for pizza and others I add to stuff.

    • 215.3
      Sally says:

      freeze it leaving head room for expansion.

  16. 216
    bp says:

    Could you substitute 2 Tspns of red wine vinegar per quart instead of lemon juice?

    • 216.1
      Marisa says:

      No. Red wine vinegar doesn’t have the same concentration of acid that lemon juice does.

  17. 217
    Virginia says:

    May I make a reply here? I have a recipe that my aunt and the lady from our local extension office helped me with several, several years ago. She knew that my recipe had oil in it. It makes 12-13 quarts and has 2 cups of oil in the whole recipe. I add 1 tbsp lemon juice to each jar (not important to what I am saying, but just in case someone mentions it, and yes that is the amount the lady from the NC State Extension Office told me to use). I just ran up on this website and now a couple more that all say do not use oil to can with. I’m honestly not sure why. Is the difference in the way you can your sauce? Most recipes I see call for a water bath, but I have always canned mine at 12 pounds of pressure for 10 minutes (per the instructions from our local extension office lady.) I am canned my spaghetti sauce this way for years without any trouble, and to now see that someone is saying we are not suppose to use oil has just floored me.

  18. 218
    Lauren Nelson says:

    I never canned before last week and never knew of the dangers of canning your own tomato sauce. I canned 12 jars last week and put in cool basement I did a water bath not adding any lemon juice or wine vinegar. Should I throw out the entire batch or can I take it out of the jars and freeze it or re-can it with lemon juice in each jar or is one week too long?

    • 218.1
      Marisa says:

      You could open up the jars, bring the sauce back up to a boil, and reprocess appropriately.

      • Anne Mark says:

        I have a similar situation, my mother in law canned my tiny tomatoes that were roasted with peppers, onions, garlic and olive oil. She cleaned the jars in the dishwasher and the sanitize setting. She boiled them for 35 minutes. All the jars “popped”. They have been stored in the pantry. It’s been warm for the couple of weeks they have been stored, up to 80 degrees in the house. If there was no boiling of the jars and no lemon juice added, what should I do with them?

  19. 219
    Connie Molter-wagner says:

    I just made tomato sauce and salsa last night with one of the recipes on line. I boiled my my jars and put the sauces in the jar but for got to do a water bath. Is it still safe to use this boil it again and the jars and than do a water bath.

  20. 220

    I never add meat to my canning sauces, and I start with 25 lbs of fresh frozen garden grown tomatoes from our yard,I add carrots onion basil thyme marjoram oregano rosemary sage and savory 1quart of olive oil 2 cups of organic cane sugar 1 cup of lemon juice 8 bay leaves and cook it down like my grandmothers did 24 to 30 hours on low heat stirring the pot about every 3 hrs, Its a long process but it is worth it in the end the sauce is dark red almost rust coloured and has a nice sheen on top when stirred.

  21. 221

    Opinions swing like a pendulum. For generations people canned meat successfully because they had to but how many stories of food poisoning from home canning have you actually heard of. I think a lot of us would be more convinced if we heard real life stories.t he Amish can extensively because they don’t believe in using electricity

    • 221.1
      Marisa says:

      You don’t need electricity to can safely. And there were many instances of food poisoning in the past. The recommendations contained in this post are not opinions, they are science.

  22. 222
    maria dibenedetto says:

    Is it safe to assume a lobster sauce is not safe??

  23. 223
    Michael says:

    My Aunt and Uncle were hospitalized 2.5 years ago with botulism. They were both in their mid 80’s and ultimately my Aunt wound up passing away. The CDC had to test everything in their kitchen to discover the cause. It turned out to be her jarred tomato sauce that she had been making and jarring annually for 60+ years. Seeing it firsthand we now know how important it is to follow food safety guidelines. My family doesn’t currently jar our sauce anymore, but have been working towards figuring out how to do it safely so we can keep the tradition alive for future generations.

  24. 224
    Swick says:

    So, I just made and water canned marinara sauce which included olive oil,carrots, 0nion, garlic, herbs, Roma tomatoes… I boiled in a water bath 45 min following a recipe on the internet yesterday and refrigerated after cooling after I found out you aren’t supposed to can sauces. What can I do if anything to re-can for gifts or at least to save for self use, such as freezing? Because it’s delicious.

    • 224.1
      Marisa says:

      You can’t can a sauce like that without a pressure canner. You could transfer it into freezer-safe containers and freeze it, though.


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