Had my first learning experience last night with my canner. I been canning now for a year. Got my pressure canner (Mirro-Magic weighted gauge) from a pawn shop last year, about this time, after looking all over and not finding one for a long time. It’s in good shape and I’ve used it a lot this last year. The gasket in it now is a new gasket, this being it’s second time under pressure. The old gasket still works, but not knowing how old it is, or how close to failure it is, I replaced it with one purchased from an on line canning supply.
Last night my seal failed after the canner had been under pressure about 40 min. It blew out at one point. I had put olive oil on it before screwing it together, so I don’t think I’ll do that again. I was canning pumpkin chunks, about 1” squares, filled the quart jars full. Had the canner steaming away at 15psi for about 40min when the seal blew out as well as the water. Two lids blew off the jars in the canneras did the contents, but the curios thing is in the jars that did not have the lids blow off, the pumpkin basically puréed itself, and the contents only filled 1/3rd of the jar. Steam is an awesome force, and that rapid depressurization was fascinating.
Could have been a defect in the new seal. olive also burns at a lower point then vegetable oils. I have used a drop of oil on old gaskets before. Make sure your seal was in the right direction etc...
Pumpkin butter is very good stuff. 9 if your pumpkin is not scorched) I would keep it in the refrigerator though.
I had trouble with a Mirro-Magic canner as well. Mine wouldn't hold a seal so I replaced the gasket (bought the new one from the manufacturer), but that one wouldn't seal either, so I couldn't get it up to pressure. I never did figure out what was wrong. Maybe like Ralph said, the gaskets are defective.
And I second the pumpkin butter. Or pumpkin pie, pumpkin pancakes, pumpkin muffins, pumpkin cake, etc. Since it didn't get to process the entire time, I'd probably freeze whatever I didn't use right away.