I processed tomato sauce last night and 2 lids weren't sealed in the morning. They all seemed sealed last night.. Can I safely reprocess them this morning even though its been 8 hrs that they sat and cooled?

  • 4
    Does this answer your question? Jars didn't seal
    – Plutian
    Aug 2, 2021 at 8:13
  • Welcome to SA! You've asked a question for which the answer is the same as another question. Please see that one.
    – FuzzyChef
    Aug 2, 2021 at 22:54
  • I don't agree that the answer linked is precisely the same, therefore I am answering. FWIW, the reason they are not the same is the linked question is about jams - which means sugar - and sugar is a preservative all by itself. Sugary stuff is different than tomatoes.
    – Mark G B
    Aug 3, 2021 at 23:15

1 Answer 1


Based on what you've told us, you should be just fine. Straight from the USDA's Guide to Home Canning (page 1-26, emphasis added is mine):

[If a lid fails to seal on a jar, remove the lid and check the jar-sealing surface for tiny nicks. If necessary, change the jar, add a new, properly prepared lid, and reprocess within 24 hours using the same processing time. Headspace in unsealed jars may be adjusted to 1-1/2 inches and jars could be frozen instead of reprocessed. Foods in single unsealed jars could be stored in the refrigerator and consumed within several days.][1]

I am assuming, though, that you used a recipe for canning tomato sauce, and followed it. Oddly enough, although we think of tomatoes as acidic, they are sometimes not acidic enough for canning. Because of this most tomato sauce recipes for canning call for lemon juice or citric acid.

Because the jars didn't seal, you don't have an anaerobic environment, so you wouldn't have botulin toxin. However, because of the cooler temperatures during the time the jars were unrefrigerated, you might have other microorganisms growing. This is where your 40-140 rule comes in. The best environment for growing unwanted stuff is when food is between those temperatures(2). This possibility would be why, if you aren't going to reprocess, you should recook and refrigerate if you want to consume the sauce in those unsealed jars. You could also freeze the sauce after recooking.

From my personal experience, I have had stews with grains begin to ferment, because they spent too much time cooling down in that danger zone. Interesting - but not an experience I want to repeat. I have also had home-canned low-sugar jams ferment because they were treated like commercial (high-sugar) jams (meaning they were left out of the fridge). I don't want to repeat that either.

  [1]: https://nchfp.uga.edu/publications/usda/GUIDE01_HomeCan_rev0715.pdf
  (2): That is degrees Fahrenheit, by the way!
  • 1
    Thank you for your answer. I am not sure where you got the idea of meat was but I looked in another spot and they said that you should not reprocess but you can cook it again and use promptly or freeze. So I did that. I actually cooked it for 3 hrs with seasoning this time and froze. Now I'm worried that it is not safe to eat later. It was canned as straight tomato sauce cooked down with nothing else added to it. Do you think it's safe to eat later? Their response was tomato sauce is very acidic and even though it should not be recanned it would be safe to eat if used now.
    – Dorene
    Aug 5, 2021 at 3:14
  • @Dorene; Actually, because of other responses to this post I went and did some research. Now, mind, I've previously done plenty of research online in the past on canning, when I needed it due to some problem or other. But my original answer to you, while not wrong, is not right, either. But neither is the jam answer linked by the previous commenter. The correct answer, based on USDA canning guidelines, is that you are just fine with these jars, and I will re-write my answer to reflect this advice, WITH the source and more detail.
    – Mark G B
    Aug 5, 2021 at 18:04
  • @Dorene; BTW, I used the meat link due to it's use of the 40-140 rule, which I thought was the most appropriate with tomato sauce.
    – Mark G B
    Aug 5, 2021 at 18:06

Not the answer you're looking for? Browse other questions tagged or ask your own question.