pressure canner cannot reach correct temp.

Asked August 31, 2013, 1:00 PM EDT

I am trying to can soup stock, which needs to be processed at 11psi. However, my canner does not seem to be able reach higher than 7 psi, though the gauge goes up to 15 psi. I had an extension agent check the gauge yesterday and determined that my gauge reads 2 psi higher than the agency's (at 11 psi mine read 13 psi), so I have adjusted accordingly (my gauge reads 9 so it's actually only 7 psi). Why can't the canner reach the appropriate pressure? is it possible my stove just does not put off BTUs? also, if I extend the processing time, is it possible to still use this stock, or do I need to toss the entire batch?

Multnomah County Oregon home food preservation

3 Responses

I'm glad you had the pressure canner gauge tested- but how frustrating you can't get the canner to hold pressure now.
It may be that your stove is not heating enough. Some stoves have a control built in that keeps the burner from overheating which would damage wiring. The large pressure canner, which extends over the edges of the burner, holds the heat in, so the burner may not operate correctly. This is true for many smooth top stoves.

It may also be that there is steam leaking from the canner somewhere. Can you identify any steam leaks?

Extending the processing time does not make the stock safe, because it doesn't reach a high enough internal temperature. Extending the time can't make up for that.

You should have 24 hours to reprocess the stock. Are you able to borrow a canner that is working? Place new lids on the jars before re-processing for the entire length of time called for at 11 pounds pressure. Or you could let the jars cool and freeze the contents. Wide mouth jars work best for freezing containers, Jar manufacturers don't recommend freezing in jars with narrow mouths since there is a chance of breakage.

Remember the toll-free Food Preservation Hotline is open right now (1-800-354-7319) and someone can talk to you if you still have questions, or you can respond to this message.
Good luck.


Hi Jeanne,

thank you so much for your prompt response. I do indeed have a flat-top stove, so perhaps that is one issue. I also contacted the manufacturer (Presto) and they had a questions about when I last replace the ring and op plug, so perhaps I'll try replacing those and see if I have better luck.

as for my current stock, I did refrigerate the jars so they'll not spoil - if I keep them refrigerator can I reprocess them (with new lids) when I get my pressure problem sorted out? or is it best to just freeze them at this point? I will see if I can check out a pressure canner from the preserve and serve Library here in St. Johns.

thanks again for your help.


You should be able to refrigerate the stock a few days until ready to re-process it. I would break the seals of any jars that did seal, even in the refrigerator. Before reprocessing, you would need to pre-heat the stock- your directions should call for ladling boiling stock into hot jars before placing them in the canner. We don’t have a way to determine how long to add to processing time if the stock and jars are cooler than that, so that probably means emptying, heating and refilling hot jars. Freezing is easier, if you have the space. Good luck! Jeanne