Someone else may have an answer for you, but when I get a chance I'll ask my DH. He's the steam-pressure expert in the family.

However, I'm confused about canning in a 12-quart Presto. How would food contained in glass jars and where air is being sucked out come into contact with anything from China?

Carol

Sorry for the confusion. I should say:

I don't use anything such a glassware, pots, etc. that come from China in contact with food. As I had a large pressure canner, but also wanted a large pressure cooker (in the 10 quart range) I thought I could also use it for canning relatively small amounts if it took the magic '4 quart jars.' This one seemed ideal - and who knows, maybe it is safe for canning even at my altitude, but until I can see an explanation as to why I am reluctant to try it.

I am uber-paranoid about botulism!

Nate

OK, I understand. It isn't the canning that's the issue (re a Chinese pc) but the cooking.

DH said if the Fissler is engineered to maintain an absolute pressure of .8 bar (11.6 psi), that is irrespective of the altitude.

That appears to be what is meant by This is one of the features of the Fissler pressure cookers that they are working indenpendently from the ambient pressure.

The ambient pressure (psi-g) varies depending upon atmosphere. The absolute pressure (psi-a) does not.

This is an unusual situation, not common with the usual range of domestic pressure cookers. However the Fissler works, it appears the mechanism is designed to maintain a consistent 11.6 psi regardless of elevation.

You may want to confirm with the company, but based on what you quote, that's what DH says it means.

(I learned something on this one.)

Carol

Wow, this is amazing. I'm still puzzled though as to how you can have an absolute pressure irrespective of the altitude. Unless it always rises to 1.8 bar, which is 1 atmosphere + .8 atmospheres? Or 26 psi? (At sea level, atmospheric pressure is 14.6 psi). I don't know.

In any case, then, I do see what they mean - but I am still not sure this is hot enough for my pressure canning - even though 11.6 absolute is 241F which IS hot enough. I'm not sure -- I think for safety's sake, I'll continue to use my pressure canner (at 15psi) [On the other hand, I just looked on wikipedia and they say this: # psia (pounds-force per square inch absolute) Â gauge pressure plus local atmospheric pressure. Replace "x psia" with "Pa = x psi". which is what I had typed. So perhaps this WOULD be good for canning. Wow!)

In any case, the pressure cooker is beautiful as a pressure cooker - I have made several things in it already and it does a great job. I've attached a link to it. It cost me a fortunate - $260 on amazon.com but it IS 10 litres. And my 6 quart Presto cost me > $100 more than 20 years ago when they were US made, so, I think this wasn't bad.

Here is a link that might be useful: Fissler Blue Point pressure cookers.

Personally, I would not trust it to can in. Also, how do you vent it for the full 10 min. before allowing pressure to build ? As you know, you must vent all canners for the full 10 min. before you build any pressure in them.
That is a lot of money for a pressure cooker. Mine was made in France, I think. Got brand new for only $15 !
It must have been a store model as it was brand new, but had not box. It was at the Goodwill. It is 18/10 stainless steel. So far it has been wonderful to use.

Yes, I know what you mean about the venting. However they also claim that they ALWAYS vent prior to closing up. However, it is possible to vent these as there is a slide switch on the handle that allows pressure to build up, or not.

Wow you got quite a deal! The Fissler is 18/10 as well. I have been told that the German standards (and possibly the french) use less nickle than the US so do NOT leave pure salt crystals on it else it will pit. FYI.

My DH used psi-a (absolute pressure) in his work, but clearly it's not the routine.

While I believe Fissler (allowing for any second-language issues), I think your decision to use the Fissler only for cooking is the most conservative and comfortably safe choice.

I have heard of Fissler but chose a Kuhn-Rikon, similarly darned expensive but beautiful quality. I also have a Fagor Duo set, plus of course the larger canning cookers.

It was still interesting to learn about this whole issue. I know there are a number of pressure cookers now which don't vent as the earlier models do. Mirro's latest canner is new-generation in that regard.

These changes do make for some challenges in regard to standard canning instructions. Hopefully at some point the NCHFP will do some expanded research on these recent designs.

Carol

I am uber-paranoid about botulism!

Then why would you even consider using an untested, unapproved pressure cooker for canning when there is no way to even verify it's accuracy or safety and which requires someone with an engineering degree to understand? Sorry but that makes no sense.

The Presto, which has been tested and approved and is in use by thousands and has been for decades, would clearly be preferable regardless of where it may or may not have been made.

Sometimes common sense just has to be allowed to prevail. ;)

Dave

Not in the slightest. I have already stated I'm using my pressure canner. Untested? Unproven? How is one to know if something is untested and unproven until you do the research?

As for Presto, I will never buy another Presto product again - like most American companies they've sold out the American people who worked for them, and outsourced their work to a low cost country with no respect for labor standards, environment, or anything else. And before you start whining that I'm a tree hugging liberal, I have to say that I'm a raving libertarian but part of being such is being aware of what makes your local (national) economy work.

I would HAPPY buy another All American Pressure Canner - they are still made domestically.

Anyway Fissler responded to me again:

Dear Mr. Justus,

We have contacted our technical department and are pleased to provide you with the
following information:

You have absolutely correctly mentioned the cooking process: Set your heat source to
high to heat up the pressure cooker. Steam will escape from under the lind handle
along with the atmospheric oxygen that can destroy vitamins. This process can take a
few minutes. As soon as the Euromatic closes and no more steam is expelled, pressure
will begin to build up. The indicator rod will soon begin to rise.

Regarding the vacuum we have to inform you, that if you will use the pressure cooker
in vacuum you would have only 0.8 bar overpressure in the pot, which will correspond
with an absolute pressure of 0.8 bar, because the ambient pressure (=0bar) will
always be added to the operating pressure. If you would use a pressure cooker under
normal atmospheric pressure and put it under pressure (i.e. 0.8 bar) and afterwards
put the pressure cooker in a vacuum, the ambient pressure inside the pot would be 1
bar plus the overpressure of 0.8 bar. In the vacuum surrounding will then be a
ambient pressure of 0 bar and therefore the pressure cooker would have a pressure of
1.8 bar at the inside.

The height level (and ambiente pressure) does not have any effect on the cooking
process because of the fact that the pressure cooker does have before closing the
same pressure inside and outside. The most important fact of the cooking process is
the over pressure which is build up in the closed pressure cooker. You can remove
from the total, absolute pressure level for the inside and outside the same ambiente
pressure, so that at the end the result will be the pressure difference which is the
inner pressure of the pressure cooker.

We hope that this information will help you. In case you should have further
questions, please do not hesitate to contact us again, we will always be pleased to
assist you.

Just re-read my last post -- didn't mean it to sound as acid as it did. I am not attacking you, Dave, or anyone here. My frustration comes with companies who, and a tax policy that promotes the practice of, outsource production to other nations with unfair and dangerous practices. Not to mention building up the industrial bases of other nations, while we destroy our own. No country can 'create wealth' on services, it is production that does this. Unfortunately we've kind of forgotten this in America.

How is one to know if something is untested and unproven until you do the research?

The testing on Presto canners has already been done by USDA/NCHFP and have the UL seal of approval. NCHFP uses them to base their research, processing times, recipes, and all the guidelines we follow on. Just like the Spanish brand Fagor, they have never tested the German brand.

No country can 'create wealth' on services, it is production that does this. Unfortunately we've kind of forgotten this in America.

Oh I agree with you in principle but the safety of my home canned food is more important to me. So I won't be sending my money to a German company selling a product that has not been tested and approved and which makes claims about their product that defy the standard, accepted practices.

Afraid we will have to agree to disagree on this issue.

Dave

Dave, as I'd previously stated: I HAVE a Wisconsin Aluminum pressure canner, a 19 1/2 quart one. I decided I was going to use that (and have been) rather than the German one. So we're in agreement, not a disagreement.

I was posting my questions in case anyone else had heard them, because they seemed odd to me. I am still skeptical that this might be correct, so won't be using it for canning. (Though, if I lived at sea level, I certainly could). I have been told by an American friend who lives in Germany that in his experience, they can things at lower pressures for longer times. I won't do that.

As a pressure cooker, I've been very impressed. I don't at this time plan to use this as a pressure canner (though if Carol's DH concurs according to his knowledge of physics that this WOULD reach pressure, it would be interesting to consider doing so. I still probably wouldn't - one of the reasons why I wanted something smaller was I wasn't sure my glass smoothtop stove could take the weight of the other canner. Kitchnaid assures me that it will, so no worries).

So I think we're more in agreement than not.

Nate

Nate, we teach that only Presto are safe to use for canning on glass top stoves. I think you should check with AA on the use of their product on your glass top stove.
I would hate for you to crack your stove top or something.

Mirro canners are now junk, in my personal opinion. I was shown the new models and how the handles have a little spring in them. That spring keeps breaking. They sold out to another company. The gal that I deal with in a prominent store said that Mirro parts are getting harder to get, too. Wonder where Mirro canners are being made ?

I have Presto, one I have had for over 30 years. Still going strong. I do have one newer model, too. I would have an AA, but I cannot lift them due to a back condition. Even empty they are heavy. I have to carry canners back and forth to classes that I teach.
Another note, this is why I like using the weight set on the Presto canner, they self vent, but of course, you still have to vent for the 10 min. before putting the weights on.

I do not like Mirro and have never liked Mirro. However, I do remember a previous thread in which KatieC gave instructions for the newest Mirro, which does operate quite differently re venting.

Nate, as I mentioned earlier, my DH is saying absolute pressure is certainly possible, especially with a more expensive (and more engineered) pressure cooker.

However, he doesn't know how the Fissler is designed or what mechanism they use to achieve that, so there's no way to verify beyond the company's assertion. While they're a very highly regarded old-line company, when dealing with low-acid product that assertion falls short of the line for complete confidence, which is why I suggested a second communication with the company to clarify.

Barring proof, your decision not to use the Fissler for canning is most sensible.

Linda Lou, I assume your pc is a Sitram? What a bargain!

One of the issues with some of these companies like Magefesa (which does manufacture 23-quart canners) is simply parts availability. I'm also suspicious of continuing parts availability for Mirro, while Presto and All-American continue to have a reliable line of parts, even for the oldest canners.

Carol

Linda,

I did check with the AA folks. They told me, essentially, that they could not claim that their canners would be safe on glass topped stoves because it is always possible that one could drop them or something like that, which would break the glass.

I did check with the manufacturer of my range, who told me that a single canner of up to 50 pounds would be fine on the top of the range.

I am still very careful; I place the pot on top of the stove, add the water from a second pot, so there is no chance of something really heavy accidentally slamming the glass.

I've done it once on this range - I used to use this canner on my last glass topped range all the time.

I'm quite sure that the AA folks are leery of the liability.

I bought the weight set when I lived back east from AA -- I REALLY don't like dial gauges. I am always worried they aren't right. Sure, you get them calibrated each year - but suppose they got dropped when being put back in the box?

Hi, I know I'm late to this thread, but I own several Fissler pieces, and I just wanted to add some helpful info.

The Blue Point has the pressure bar - this allows you to tell if the unit is under high pressure or medium pressure.

I have successfully preserved everything from cucumbers to salsa to spaghetti sauce to jams to carrots using my small 6.4L pressure cooker. The Quattro set is my pressure cooker.

It is self venting, no need for that old timey 10 minute pre-venting step. I use the vented rack, fill 1/2 way with water, go to high or medium pressure, reduce the heat, and wait 10 or 15 minutes depending on the recipe.

This unit is bullet (dummy) proof.

I'm glad you are happy with the brand Emily but I curious about how you are compensating for the processing times?

Since the published processing times wouldn't be valid for a cooker that small and you've further eliminated the 10 min. venting time, you've been substantially UNDER-processing the foods. Have you added time to the processing? If so, how much?

Dave

I agree, you still must vent for a full 10 min.

If it doesn't hold 4 qt sized jars it is too small for canning in. I am not sure how large yours is.

I use my (10Q) Fissler to pressure can my low acid veggies and meats. It holds 4 quart jars and 7 pints. I live at sea level and can everything at the 2nd bar (the highest it will go) which is 11.6 psi. It does vent itself and then the rod closes and pressure builds. When the indicator is at its 2nd bar (meaning at full pressure), I start my timer for the amount of time listed by NCHFP for whichever ingredient requires the longest processing time. For example, tonight I made tomato soup that had beef/chicken broth and bits of bacon, so I followed the spaghetti sauce with meat guidelines (as it was thicker soup) and processed the pints for 60 min. I never vent or cool the cooker, but let it cool on its own.

Since the NCHFP calls for weighed PSI @ 10 and dial PSI @ 11, and my cooker gets to 11.6, I feel comfortable using it as a canner.

Just my 2 cents

Not meaning to diverge from the last post. This was the most relevant thread of two when I typed in "Kuhn Rikon". The SI valve is leaking and we can't get the 3.5 quart pressure cooker up to pressure. Has anyone out there a source for this $3 item which vendors would like to sell for 4X that? The pressure cooker has been in use since 2009; no component should be giving up the ghost this quickly. Thanks for any experience/info