Found My Mom's Pressure Cooker
My mom gave me her pressure cooker several years ago, but I've never used it. I dug it out of a very high cupboard and decided to learn how to use it. The lid was on tightly ... so tightly that my husband had a hell of a time removing it. It appears that either mineral deposits or perhaps microscopic bits of food residue had formed an almost hermetic seal. These deposits were all over the interior of the pot and the seal. I tossed in some kosher salt and began giving it a hearty scrub. The rinse water was dark grey. I did another round or two of salt, then a round with baking soda and vinegar. The pot feels smooth inside, but there are some small grey spots and the seal still has light colored spots (possibly mineral deposits) all over it.
Should I toss it? I was hoping that this would be an oldie but a goodie, but now I'm afraid that the pot has been severely compromised. If only she'd not locked the lid on all those years ago. It has probably been 20+ years since it was last used.
The handle says Presto Supreme Aluminum Industries Limited. It was made in Canada. Is it safe to use, health-wise? I can get a new sealing ring online, but should I bother?
My wife has her mother's Presto pressure cooker from the 1970's. Recently we replaced all of the rubber seals, relief valves, etc. It cost almost as much as a new 4-qt pressure cooker, but now it's good as new. We would not have done this except for the sentimental value.
I've ordered a new stainless steel Fagor Chef 8Qt pressure cooker. I may yet order a new gasket and see if I can make use of the smaller aluminum one. I believe it is only a 3Qt., so a little less versatile. I don't know if my mother ever used it for more than potatoes to be mashed. It could handle a pound or so of meat, but not a lot more. I think a bigger one will be used a lot more often, for things like pork shoulder, brisket, ropa vieja, etc.
The gray color is normal. Cook scrambled eggs in an aluminum pan and they will become gray. Rub bare aluminum onto a white cloth, and it will become gray. Aluminum will naturally anodize, but constant scrubbing will remove it.
I probably have the same pressure cooker at home. Mom got it back in the 50's-60's.
I agree with paulj that probably the gasket was what stuck parts together. Just get a new one and things will be fine.
I have an older (70's?) aluminum Mirromatic pressure cooker, with an interlocked lid and pressure escape valve, and it works beautifully. I just made osso buco last night in it.
It doesn't sound like there is any problem with aluminum body, though you could scrub it some more, or use Barkeepersfriend (an oxalic acid cleaner).
But the rubber parts do need to be replaced, both the main gasket and the rubber safety plug.
Do you have the weight? Make sure the central vent tube is clear.
Does it have a lid interlock? In the mid 1970s, Presto added an interlock which kept the user from opening the lid when there is pressure. Initially they used a vent near the rim with a plug that rose under pressure. It's a nice indicator that pressure is starting to rise. If you have that, make sure that plug is clean and moves freely. You may need to take it apart to clean it properly.
If the PC is older than that, and does not have such an interlock, it is still quite usable. You just need to be more careful when using it. Specifically, do not try to open the lid without first removing the rocker weight. That's a good idea even when it has the interlock.
The handle (both top and bottom) can be unscrewed and cleaned, though I don't think that affects operation.
I suspect the initial difficulty in removing the lid was just due to the rubber gasket sticking.
has a picture of the lid interlock. That has a gasket as well, though that doesn't need replacing as often as the main gasket.