Intro and Chicken Stock question

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Joined Apr 16, 2006
OK.  According to the manual, what I have is intended for canning as well as cooking.

And I haven't killed anybody.

Yet.
 
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Joined Feb 1, 2007
Is there some reason to believe that when my pressure cooker says it's working at 15 psi that it is not actually doing so? 

Unless there's some mechanical problem, there's no reason to believe that at all. But there's more involved than the actual pressure peak.

When you read a canning recipe the time/pressure figures are based on the volume of a canner. There are minor variations, make to make, but call it 21 quarts on average, vs the 8 quart capacity of your cooker.

So, now you decide to can something. Chicken stock, to put a point on it. The recomentation for chicken stock is 20 minutes for pints, 25 minutes for quarts, at #10 at sea level. Timing starts when the gauge or jiggler indicates ten pounds. So far, no problem.

But here's the deal: The time/pressure figures takes into account both the time it takes to heat the unit to the #10 mark, and the time it takes to cool down naturally. And that's where the difference lies. Because your cooker is so much smaller, it both heats up and cools down exponentially faster than a canner. And, while this may not actually matter, in practical terms, you have no way of knowing. If I use my 22-quart canner, there's no question that the contents reached, and were held at, 240+F. But the same cannot be said about your cooker. And that's where the potential problem lies.

The key word in all this is "potential." Unlike the USDA and FDA---which uses the words "untested" "potential" and "unsafe" as synonyms---my approach is that a person has to understand the process, and the risk/benefits involved. If knowing them you choose to proceed with a non-recommended procedure, you have at least made an informed choice. But the choice should be based on the "informed" part.

Would I eat stock you've canned in your cooker? Unhesitantly. But that's because the risk we are guarding against has been greatly overplayed by the USDA in the first place. But that's a different issue.
 
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Just an fyi in the second link Pete posted.

Because most people connote the word "gauge" with a "dial gauge" their use of the word "gauge" is a little ambiguous.

Just keep in mind that a jiggler is, technically, a "weighted gauge," and that will keep everything straight.
 
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Grumio, you may or may not be aware, but we have several real authorities on pressure posting here. AmazingGrace, for instance, is a real pro when it comes to pressure cooking, and an absolute golden resource on that topic.

More to the point, there are a number of serious canners, including at least one commercial canner, who are members.  So, if there's ever a question in your mind, just start a thread. I'm sure these folks would be happy to jump in.
 
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Joined Jul 28, 2006
KY, thanks for the kind words.  /img/vbsmilies/smilies/smile.gif
 
OK.  According to the manual, what I have is intended for canning as well as cooking.

And I haven't killed anybody.

Yet.
I purchased an 8qt Presto Pressure Cooker at Amazon.com.  It was described as a pressure cooker/canner.   Even though I had no interest in using said pan for canning,  I did call Presto for more information.  I was informed in no uncertain terms that it is NOT a canner,  and Presto no longer promotes it as a dual-function appliance.  Furthermore,  they take no responsibility for the vendor at Amazon continuing to advertise it as a cooker/canner. 

Even if/when a manual says it may be used for dual purpose,  it may not be in the owner's best interest to try to can with it.  I  have a 10qt Fagor which is also touted as a cooker/canner.  IBut it too small to have been rated by the USDA,  and because the timing for these smaller units are so vastly different than for larger ones,  no reliable time charts have been developed to use with them.  It's not worh the risk to me or my family to do any sort of guesswork,  especially with untested recipes [that is "untested" as in regards to having been proven by a reliable test kitchen---not my own home experiment].  In addition,  even if I were inclined to try it out,  I am at 6,300ft above sea level,  which introduces another issue to the already iffy situation. 

Some people do often refer to pressure canners as "cookers".  If you will tell us about your pressure cooker,  perhaps we may be able to comment further regarding its worthiness as a canning vessel. 
 
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Thanks, KYH, AG & PM for the info.

I canned stock & glace in my pressure cooker (an 8-quart Mirro with a 5-10-15 weight gauge) for a couple of years, and it worked perfectly.  Then I finally got a modern refrigerator with a decent sized frost free freezer.  I freeze my stock now.  I would can again, though, if the need arose.
 
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Nothing wrong with freezing it.

I noticed, though, that I was less likely to grab a container of it from the freezer than I was to open a jar. So I started canning all my stocks instead. Has to do with me, though, rather than any intrinsic benefit to one method or the other.
 
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    I freeze my stock two ways.  The smaller version is frozen in a cupcake pan, I take all the frozen little cupcakes of stock and put them all in a large Ziploc bag.  This makes for a good size when adding stock to a sauce or gravy, etc.  The larger version is frozen into a 4 cup Tupperware and then removed and placed in the large Ziploc bag.  This 4 cup size seems to work well with various dishes, like rice dishes, gumbo, pot pie, etc.

  dan
 
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KY and Amazing - wonderful examples and research.  I enjoyed reading them immensely.  My analogy of canning that I tell students is this: You may choose to wear a seat belt or not to wear a seat belt.  Chances are, you won't have a wreck on this particular car trip.  But if you should wreck, unrecoverable disaster may occur.  It's simple - just wear your seat belt. 

Likewise, can your foods according to the "rules" of food safety.  Consult processing authorities on matters you are not familiar with instead of winging it!  The information is readily available, and there are numerous reliable resources.  Ball, Presto, All-American, USDA, etc.

Thanks for spreading the word. /img/vbsmilies/smilies//wink.gif
 
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Jamlady, I was hoping you'd weigh in on this.

Great analogy with the seat belts. I'll probably steal it from you. /img/vbsmilies/smilies/thumb.gif
 
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Joined Jul 28, 2006
When we lived in PA, I had access to my MIL's equipment,  I canned a lot,  and often.  Taking advantage of nature's bounty is something dear to my heart.  HubbyDearest and I moved too far from them, she has passed on,  and FIL has other interests,  so the canner and accessories are no longer available.  However,  my rural community has a county-run and staffed canning facility.  It is free to all county residents.  We bring our jars and other necessities along with the produce or whatever else is being canned.  We work with the staff getting the items ready,  and then they take over with the actual processing.  Where it might take several days working at home,  the same can be accomplished in only a few hours at the canning center.  In addition,  there is absolutely NO guesswork.  It's all done according to proven timing charts.  Such a blessing!!  I wonder if this is unique to my area,  or do such facilities exist other places? 
 
929
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Joined Jul 28, 2006
Thanks, KYH, AG & PM for the info.

I canned stock & glace in my pressure cooker (an 8-quart Mirro with a 5-10-15 weight gauge) for a couple of years, and it worked perfectly.  Then I finally got a modern refrigerator with a decent sized frost free freezer.  I freeze my stock now.  I would can again, though, if the need arose.
Today I went to Wearever's website and looked up Mirro pressure cookers and canners.  While they produce pressure cookers as small as 4qt, their  smallest pressure cooker/canner is a 12qt size.  Then I called the toll-free number [1-800-527-7727] and spoke with a consumer representative for Mirro products.   She said the smallest pressure canner they now sell is 12qt.   I asked about using an 8qt for canning,  and she said "We don't recommend it."  Then I asked her when they stopped recommending the 8qt for canning.  She said "About 10 years ago."    Grumio, because the manual for your cooker gives directions for canning,  I'm guessing it is at least that old,  and the instruction manual is obsolete in regards to it being used for canning foods.  Whether there is a real risk, or nothing more than a perceived risk to continuing to can with your pressure cooker,  I don't know.  But one thing is certain,  both Mirro and Presto are covering their collective fannies on this issue by not recommending their 8qt pressure pans for use as canners. 
 
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Sorry for the hiatus but I've been on the road a bit for work. My Pressure "canner" is a 23 Qt Canner which can also be used as a cooker, not the other way around. I'm not using a silly little 8 Qt cooker as a canner. I've taken it down to my local Ag Extension for calibration once a year and they have assured me on multiple occaisions that it's perfectly adequate for the job, even for low acid foods.

I hope that clears up some confusion.

Really good info in this thread, even on the side track.
 
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929
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Joined Jul 28, 2006
Sorry for the hiatus but I've been on the road a bit for work. My Pressure "canner" is a 23 Qt Canner which can also be used as a cooker, not the other way around. I'm not using a silly little 8 Qt cooker as a canner.

I've taken it down to my local Ag Extension for calibration once a year and they have assured me on multiple occaisions that it's perfectly adequate for the job, even for low acid foods.

I hope that clears up some confusion.

Really good info in this thread, even on the side track.
Although it may not be clear to everyone,  I am assuming that it is the canner that you get calibrated once a year, since pressure cookers do not need this sort of adjustment. 
 
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Joined Feb 1, 2007
Nor, for that matter, do canners that use jigglers.

Dial gauges, however, should be recalibrated as necessary.
 
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Joined Apr 16, 2006
AG - My cooker is closer to 20 years old - rather amazing that I still have the manual!  It lists their two & a half quart cooker in the canning chart, as well as the 4, 6, 8, etc.  I wonder what caused the CYA move - change in the equipment itself, or some belated food-safety discovery (real or in the legal dept's fevered imagination).

& KY - I always found something ineffably cool about having homemade, home-canned stock on hand, in a way that having frozen stock just doesn't match at all.
 
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Although it may not be clear to everyone,  I am assuming that it is the canner that you get calibrated once a year, since pressure cookers do not need this sort of adjustment. 
If it has a dial gauge (whether it's a cooker or canner) it should be recalibrated regularly, what "regularly" means is up to each individual. This isn't nearly as important for a pressure cooker since you're eating the food right off of the stove. Canners, however, are employing a pretty exact science and therefore your equipment should also be pretty exact. Your local AG extension office will do this for free if you lug your canner to them. I try to do this once a year at the end of winter.

I didn't just make up a reason to head to the local extension, it's a pretty common factoid in the canning circles I run in and the boards I read. 
 
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Joined Jul 28, 2006
I didn't just make up a reason to head to the local extension, it's a pretty common factoid in the canning circles I run in and the boards I read. 
Everyone should make a regular practice of getting the gauge recalibrated.  Even those whose canners have the weighted regulators should check in at the local extension periodically.  There's always something they can learn [or, quite often unlearn] regarding equipment and procedures. 
 
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Joined Jul 28, 2006
  I wonder what caused the CYA move - change in the equipment itself, or some belated food-safety discovery (real or in the legal dept's fevered imagination).
In the years since you purchased your PC,  a lot has changed, starting with the food itself.  For instance, tomatoes have long been regarded as a high-acid fruit,  and could be treated with [almost] reckless abandon in regards to canning.  However,  the tomatoes being grown today for commercial use,  as well as many of the seeds and seedlings available to home gardeners,  have been "de-acidified" (probabaly not a real word,  but it works here).  As a result,  older time tables and canning methods can no longer be trusted. 

For many years,  the home canner could rely on the equipment makers for time charts and other processing information,  including the type and size of the canners they could use.  Enter now, stage left:  The USDA.  This fine organization tests canning equipment,  and tries to ensure that the information released to the consumer is accurate.  Because of the problems that occur with smaller pressure cookers [canner-wannabees], the USDA stopped testing cookers under a certain size, and therefore no reliable time charts exist for processing foods in these smaller vessels.  It was believed that adding a few more minutes under pressure would compensate for the accelerated cool-down.  But considering all the factors at play,  it's just not that simple.  Intervening variables such as allowing for altitude,  make it very difficult, if not impossible, to provide accurate time charts for anything smaller than a 12 qt canner. 

Rather than just issuing a statement saying anything under a certain size may not be called, or sold as, a canner, the USDA went soft,  and says they don't recommend canning in smaller cookers.  This, of course, continues to create confusion and contention. 
 

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