Crusty Tuna Jars

Asked October 5, 2019, 4:06 PM EDT

After pressure canning my tuna, some of the jars were crusty on the outside and the water had oil in it. Is this normal or did I overfill the jars. I pressure cooked 1/2 pints for 100 minutes at 11 lbs pressure.

Columbia County Oregon

1 Response

Hello there and thank you for submitting your question to Ask an Expert - A FREE service of Oregon State University Extension.

There can be a couple of reasons why there would be oil in the water and food on the outside of the jars. The jars may have been filled too full and they boiled over in the canner. Another reason could be if the canner pressure was fluctuating a lot during the canning time or if the pressure in the canner was released too quickly. To prevent this in the future be sure that you leave 1 inch of headspace in all of your jars and also keep the canner at an even pressure on the stove for the full 100 minutes. After the canning time has finished, turn off the stove and just leave the canner to cool naturally. Do not attempt to release the pressure or artificially cool the canner. If you had any jars that did not seal you can put them in the refrigerator to eat first or freeze them. You only have 24 hours to reprocess if not sealed. You can also refer to our Canning Seafood publication here:

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