Pressure canning tomatoes

I bought a pressure canner for the first time, especially so I could can tomatoes without having to add extra acid. (I tried using citric acid for the first time last year, using water bath, and the results are very sour!) I know the pressure canner allows you to can things that don't have more acidic pH, like other vegetables, meats, etc. But the instructions say I still have to add all the extra acid (lemon juice or whatever) even with the pressure canner! I'm so bummed! Is this really true?!

Answers

  • Michelle D
    Michelle D Posts: 1,465 ✭✭✭✭✭

    Hello @elchan7826 welcome to the forums!

    Yes, it is true that you will still need to add acidity to your tomatoes even for a pressure canner. Using vinegar as an acid instead of lemon juice or citric acid is an option but will cause flavor change. Adding the acidity is usually offset with sugar. That is why so many canned tomato products are sweet.

  • Torey
    Torey Posts: 5,640 admin

    Welcome to TGN's forum @elchan7826.

    How much acid did you add? I've never used citric acid, only lemon juice. Never had an issue with the tomatoes being too sour.

    I've also never pressure canned my tomatoes. The times for quarts for water bath is 45 minutes and for pressure canning it is 25 but it takes time to get to pressure and then time to cool down before removing the lid so the total time process is about the same.

    Lately, I have started freezing my tomatoes whole. If you want to can them, they are so easy to peel as they are thawing. If you just want to leave them frozen whole, they are very convenient; just take what you are going to use out of the bag. They keep very well.

  • VermontCathy
    VermontCathy Posts: 1,980 ✭✭✭✭✭
    edited July 2022

    @Michelle D Can you explain why pressure canned tomatoes would require acid?

    Many pressure canning recipes lack acid. For example, raw chicken can be canned in a jar with nothing else added. Part of the benefit of pressure canning is that temperatures are high enough to kill botulism organisms, while water bath canning does not, so acid is needed in water bath canning to prevent botulism organisms from reproducing.

    That said, tomatoes are normally water bath canned with acid. A good recipe should not taste any more acid than the commercially made tomato sauce you buy in the store. I think you just need to look at a wider range of published, approved water-bath tomato recipes. They will contain acid, but should taste no more acid than spaghetti sauce or pizza sauce.

  • Michelle D
    Michelle D Posts: 1,465 ✭✭✭✭✭

    @VermontCathy I don't know enough about the science to explain the why. I do know that all of the proven trusted recipes from credible sources that I have ever found say that acid is required for safely canning tomatoes.

    I do know from when I was Serve Safe Certified that tomatoes are one of the top 10 most deadly foods if not handled properly. It has been awhile since I took the class so I can't remember all 10 but tomatoes were a big one.

  • VermontCathy
    VermontCathy Posts: 1,980 ✭✭✭✭✭
    edited July 2022

    @Michelle D I just looked in my copy of Putting Food By, 3rd edition. It contains a discussion of canning tomatoes to prevent botulism, and discusses both water bath and pressure canning.

    The pressure canning technique it describes is done on chopped tomatoes, apparently with nothing else added. It specifically notes that you cannot safely mix the tomatoes with other vegetables when using this technique.

    It also notes that texture and food quality of tomatoes suffer when they are pressure canned.

    I'm not surprised that the vast majority of trusted recipes say that acid is required for safely canning tomatoes, but I strongly suspect that 95% of those recipes are for water-bath canning, not pressure canning. Water-bath canning is by far the most common technique for preserving tomatoes, and it definitely requires the addition of acid.

  • LaurieLovesLearning
    LaurieLovesLearning Posts: 7,519 admin

    @elchan7826 Having never had a pressure canner, I can't really weigh in on this discussion, but would like to welcome you to the forum.

    Please let us know what area you are from in the Introductions section.

    Thanks! 😄

  • elchan7826
    elchan7826 Posts: 8 ✭✭✭

    Thank you for the replies! I knew this would be a good place to ask this question. I have been water bathing tomatoes for years, always used lemon juice. Leaves a bit of lemony flavor, so I thought I'd try citric acid last year. Whew! It's tart! Have to add sugar to anything we make, even stirred in baking soda to neutralize! But I have also read that citric acid is not that good for you (just as a plain chemical) so I don't want to use it anymore. I have done frozen tomatoes as well and really like them that way, but trying to find ways that are shelf stable also. May try dehydrating some. So I still don't get why they need acid! If you can pressure can MEAT to prevent botulism, why can't it work for tomatoes? May just be one of those mysteries I will have to accept. 😏 Laura

  • Michelle D
    Michelle D Posts: 1,465 ✭✭✭✭✭

    @elchan7826 I like using my dehydrator for a lot of things including tomatoes. I blend some of them into a powder after drying. Have you used tomato powder?

    I have a chart of ratios for rehydration tomato powder depending on what you want to use it for. I'd be happy to share it if anyone is interested.

  • elchan7826
    elchan7826 Posts: 8 ✭✭✭

    That would be great, Michelle! My oldest daughter, who has never been much into growing stuff, etc., suddenly is becoming a "farmer," sensing the changing times and the need to provide more for ourselves and others! She's the one who suggested we dehydrate tomatoes! 😁 One thing I have done is make a lot of kale powder. Do you need email or can you post it here? Thanks!

  • Michelle D
    Michelle D Posts: 1,465 ✭✭✭✭✭

    I will start another discussion with the information in it since it is kinda a separate topic than the original purpose of this discussion. I will tag you in it @elchan7826.

  • elchan7826
    elchan7826 Posts: 8 ✭✭✭

    Someone asked amount of citric acid; recipe calls for 1/2 t per quart. In the past I have actually added less lemon juice than stated with no problems.