I find that my canners all weigh about the same. It does take a bit more heat for the larger canners. I haven't noticed a big difference between the canners on depressuring, really haven't noticed. There might have been a difference, but don't remember.

Are both of the canners the 3n1 weights? I do know what you are talking about since I have the same weights.

Hi Myfamilyfarm,

Thank you for your help! Yes, both canners I use the 3:1 weight. I think I like the 16qt better. I wanted the larger canner to stack pints but now think using another 16qt would be better. It took too much heat (high) to maintain pressure in the 21qt, yet the 16 Qt maintained pressure on low. You learn you grow ;-)

Michelle

I don't know that model, but I can think of one reason that a pressure canner might need higher heat to maintain pressure and loose pressure faster when cooling and that is an old gasket or ring. I know when I replaced the gasket in my pressure cooker (different maker/model) after years of use I seemed to be able to use lower flame level.

It doesn't necessarily mean a cooker would not meet the recommended pressure whilst processing the food but does mean the cool-down time, which is actually part of the processing time might be compromised by being shortened. Gaskets, even those for old models, are relatively inexpensive and it might be worth it to replace it. I would do that automatically if I were buying a used pressure cooker, anyway. Rubber seals harden over time, loose their elasticity and even stretch.

The 21 QT appears to hiss some around the vent pipe AFTER the heat was off and the weight rocking stopped
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
You have already found out where the problem is.

The vent pipe needs to be taken off and reinstalled.
JMO

Hi seysonn , I started to wonder about that as I was typing the post LOL! Will the rapid depressurization affect the food I canned? I canned soup and some beans in pints- I always error on the side of cooking a little too long so PC'd it for 90 mins instead of 75. Also how do I get that vent pipe out? Do I use a screw driver on the bottom ( which I have) or some sort of wrench on the top. If I do need a wrench do you happen to know the size or type ? Thanks !!!

Michelle

Hi calliope 6,

The gasket was flexible and it had no cracks and the lid fitted tight. In fact it was hard to get the lid on until I applied some vegetable oil around the rim. But will still look into getting some gaskets.The good news is both of my canners use the same size gasket. Yet, if the 21 Qt continues to need med to high heat to maintain pressure, it might be more cost effective for me just to use 2 - 16QT canners since I can keep them at a low temp. I really love my 16 QT 7B Presto, but not liking this 21 QT.

Thanks!

Michelle

I love that all of my canners, except the newest one, take the same gasket, lid, weight. If I can't find one, another one will work.

If it's hasn't been used for awhile, that seepage around the vent pipe might disappear, otherwise, see if you can tighten it up. I've found over the years with these models that when they sit, they need a time or 2 to get back into the 'groove'. try to can some water in jars and see if the vent pipe settles down.

I would think if the pipe was leaking enough for the food to be hurt, it would have a hard time maintaining pressure. I know we recommend the 10 minute cool down, but before this newest recommendations, we did ok as long as we processed at the right temps and length of time. I personally think the cool down time helps on some of the siphoning.

I have both sizes, and I use the bigger one more, unless I just have a small amount (that is almost never for me). My son just brought me a even taller BWB pan that someone was throwing away. I think it will hold 3 stacks of pints and it uses the same trivets as my canners.

Marla

The simple answer to your posts title is NO. No canner should cool down that quickly. 30-40 mins. is the norm and the bigger the canner, the longer cool down takes so something is clearly wrong with it. Should it be used? Not until the cause of the problem is identified.

Does it affect the safety of the food? It can. The normal cool down time is used when computing the length of the processing time required. Since you added extra time to it this particular batch is probably sufficiently processed.

But as to the cause, that would require more info. I am assuming that you already know that 1 quart of water isn't sufficient for processing - testing perhaps but not processing - and that the 21 model will need somewhat more water than the 16 will for normal processing.

Second, "leaks" aren't always visible. Multiple small leaks around the gasket is a possible cause so replace the gasket. The leak around the vent pipe isn't normal - any small pair of pliers can tighten/remove it if you don't have access to normal tools. Plumbers tape (white teflon sold at any hardware store) 2 wraps around the base will seal the leak. Same holds true for the base of the gauge.

Then test it again and see what happens. If that doesn't fix the problem then I suspect it is the quality of the aluminum used to make it as it should weigh more than the 16 qt does.

Dave

A simple soap water can tell you IF IN FACT THERE IS A LEAKAGE around the vent pipe. I would do that before trying to mess with the vent tube. Also do the same soap bubble test on other possible places. ALSO, try to clean the inside of the weight that sits on the vent tube.

If not the vent tube, then there is a leakage somewhere else. Depression to to cooling CANNOT make that much difference.

Hi Dave and seysonn,

Thank you both so much for your help! Thank you to everyone who tried to help me . I happen to have an extra vent pipe since thought I would need one for my other canner but once I got it found out a new vent pipe had been installed. I found a wrench and took off the vent pipe before I read the suggestion about checking for bubbles. I placed the gasket from my other canner in it since it uses the same part and tested it. With the new vent tube I did not hear hissing after turning off the heat but did notice some bubbles when I placed some dish washing detergent around the vent pipe. I got a few bubbles around the safety valve but not much. I was squirting detergent everywhere LOL! Even tried around the rim and no bubbles. It's just strange if it was leaking in a major way why would it come up to pressure with the weight and maintain it? I'm pretty bummed :-(. Might go to Home Depot to get that Teflon tape. Right now might just place that PC on a shelf and not use it. I've tested it about 4 times and its still depressurize ng in about 12 mins.

Teflon tape will make a big difference. Sometimes that teeny tiny bubble making spot will STOP as soon as you use the tape.

I have to can up some beef broth, so I will use the same model as your question and time the depressuring time. Do you use gas or electric? And do you remove the canner from the heat, or allow the burner to cool down?

Marla

I haven't got any experience with pressure canners (or pressure cookers) but it seems to me the reason why you have to keep the 21 qt on high when using is because of the pressure that is escaping. And the fact that you are using high heat is also the reason why the pressure in the canner isn't dropping. The high heat is cancelling out the pressure leak and vice versa. Fix the leak and you will probably be able to use a lower heat.

Rodney

I just canned up some beef broth in the same model canner that you are asking about. After removing the canner from the heat source, it has taken less than 20 minutes until no more sound or hissing. It might have been 15 minutes, but I know it's less than 20.

This canner doesn't leak anywhere and the gasket is good.

I don't have to be on the highest temp (I'm using a regular electric burner type of stove), I use between 7 and 8, with 10 being the highest.

Hope this helps you.

I agree with Rodney.
It only takes small amount of leak to bring the pressure down.

You should've used teflon tape on the vent pipe before installing.(Clockwise, looking from bottom, Pulling the tape fairly hard while wounding). You cannot get a good seal with metal-to-metal thread UNLESS it is a washered type.

Hi Rodney,

That makes sense! I'm going to get some of that Teflon tape from Home Depot and see how it goes.

Hi Myfamilyfarm ,

This gives me hope! At least I know it doesn't take 30+ mins to depressurize like my 16 Qt. hopefully with the Teflon tape sealing the vent pipe it will take longer to depressurize. I have a gas stove and the flame is touching the canner, with the other canner the flame is much lower.

Thanks!

Hi Seysonn,

I will get the Teflon tape tomorrow and see how it goes. I didn't tighten the vent super tight since was afraid of damaging it so should be able to get it off to apply the tape.

Thank you!

mypolar, glad I could help since I have the same canner and have used it for years without any problems. Like I said, I don't use the little ones much, since I got the 2 21/22 qt ones.

As far as the weight, I don't notice a big difference between the 2 sizes. One day, when I get my certified scale in the house and remember, I'll weigh the 2. I know my smaller ones are older than the 70s.

Marla