I wanted to make and can, my Grandma's tomato soup. However I don't have a pressure canner.

I made the soup in a 15 PSI pressure cooker and then poured it into sterilized jars and then canned it in a water bath canner, but now I am second guessing myself.

Is this safe?

  • 1
    I'm not sure if you were trying to imply that this would have been safe if the recipe didn't call for carrots, but it wouldn't - even plain tomatoes need pressure canning.
    – Cascabel
    Oct 25, 2012 at 16:32

2 Answers 2


No, it isn't safe, water bath canning is only safe for high-acid foods as the acid kills botulism. Low-acid food must be processed at 240F, 116C, and that can only be achieved in a pressure canner.

When you pressure cook the soup it kills the bacteria, however when you then transfer it to the sterilized jars it could be contaminated on the way, and then the water bath won't be hot enough to kill the bacteria.

  • This is sound advice. The only way this is safe is if you will then store the jars at low temperature: below 3 degrees C (38 degrees F). Oct 25, 2012 at 9:23

Even if there weren't issues of re-contamination (covered well by GdD), when you use your own recipe, its difficult to know the required processing time (it can generally only be determined by careful measurement with special equipment). So you may not have actually sterilized it when pressure cooking.

Is freezing an option for you? I suspect the soup would hold up well to being frozen (but, of course, I don't know its full list of ingredients).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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