Pressure Canners

[retromania]

I love pressure cookers and I have canned in my Mirro-Matic "8", but can someone tell me why most of the pressuer canners have a pressure guage and a pressure weight? Seems if you have one, you would not need the other. Obviously I don't know. My guess would be it has something to do with altitude. Am I right?

 

[sudsmaster]

The pressure weight is for setting the pressure. The gauge is for indicating that the proper pressure has been reached. It's simply informative. Of course, that's if the gauge is reading correctly, which is not necessarily a given. A lid with a gauge that is subjected to shock might register the wrong pressure, and might have to be recalibrated. But given my druthers I'd rather have a pressure cooker with the gauge than without one. The added pressure gauge adds cost to the cooker. For commercial operations, the gauge might be required, so as to confirm that proper pressure has been reached (for food safety/code). For home use, it might not be required but sure is nice to have.

 

[retromania]

Thanks. That makes sense.

 

[tomturbomatic]

Most canners had a gauge because they only had a 15 lb weight or just a petcock you closed after the air was exhausted. You had to regulate the heat to prevent the pressure from going over 5 lbs for high acid foods like tomatoes and 10 lbs. for low acid foods like string beans and some meats and combination foods, while beef and some other meats take 15 lbs. Mirro came up with the 3 pressure regulator first and then Presto introduced the break apart pressure regulator. Each gave the option of 5, 10 or 15 lbs of pressure, but that was really only good from sea level to 2,000 feet. You are right that adjustments had to be made for higher altitudes because of the lower boiling point of water with increased altitude and decreased air pressure. At 2,000-3,000 ft, you need 11.5 lbs of pressure, 3,000-4,000, 12 lbs is required, etc. In those situations, you have to watch the needle in the gauge and adjust the heat to keep the pressure from going too high. Mosdt canning books said to have the gauge tested at the local home extension service bureau each season to make sure it is still accurate. I do not know if such services are available today.

 

[sudsmaster]

Thanks, Tom. Your answer is more accurate and more complete than mine. I recently got a Mirro canner with three different weights (5, 10, 15) and no gauge, so that sort of colored my experience. Also have an old Magic Seal canner that is still in the process of restoration (mainly, polishing the exterior) that I picked up for a pittance at a Goodwill. It has a nice gauge on it, but just a single weight, which makes sense.

And then there are the pressure cookers with a selectable pressure control - like the Tramontina I picked up a while ago that has a high and a low setting.

Which is better, multiple weights or single weight and gauge? Well, I'd say I'd still like both - multiple weights AND a gauge. Perhaps that way one wouldn't have to be so fussy with the heat setting to maintain an exact pressure - just set the weights or lever to the desired pressure and then use the gauge to confirm.

As I gather, the reason for more pressure at altitude is because the pressure settings on these cookers are not absolute, but rather relative to atmospheric pressure. The key to canning is temperature, not pressure, so due to the lower atmospheric pressure at higher altitudes, the pressure setting (and reading) must be increased to maintain the same safe canning temperature. At sea level the temp of a 15lb cooker will be about 255F. A 10 lb setting will be about 240F, which is the minimum temp for low acid foods. At higher altitudes, however, it could take 12-15 lbs to get to and maintain 240F.

 

[retromania]

Thank you...

Thank you all for explaining it to me. I probably won't be doing any more canning until seasonal vegetables come in.

 

[tomturbomatic]

Suds-
If you are below 1000 ft, the fixed regulators work well. The thing about the canning process is that you lower the heat when the canner hits the selected pressure, but then as the stuff in the jars gets up to temperaure, the pressure will start to climb on the heat setting that was maintaining it, so if you only have the 15 lb regulator, you have to watch the dial and lower the heat again, but if you are using a 5 or 10 lb regulator it will just jiggle and release the extra pressure so you don't have to run the risk of having the pressure go too high if you are not there to turn down the heat. That is more likely to be encountered if you do cold pack canning than hot pack.

 

[sudsmaster]

Well, I'm at about 50 ft, just above the tsunami zone . That is, if the old reservoir dam in the hills doesn't burst first. In any case, good info. I got out my old Presto book (came with an order for new gasket for the Magic Seal), and it gives incremental readings, like 11 lbs and 6 lbs for various things. Although I'd guess that 10 lbs and 5 lbs would be close enough, maybe with a couple of extra minutes. I am wondering if it would be a good idea to add a pressure regulator to the Mirro. I like that it has multiple weights, and the construction seems relatively good. The gasket looks like silicone rubber and probably would last a long time, as well. Saw the 22 qt Presto online for less than I paid for the Mirro locally, but it doesn't appear to have multiple weights, just one 15 lb weight. Some reviews complain that it's cheaply made.

Anyway, I probably won't be canning as well until late summer. So far I've only done boiling water canning of fruit: jams and conserves. And that was quite a while ago. They came out nice. It would be nice to can some tomatoes from the garden this year.

When I bought this place, as is, the cupboard in the covered patio was filled with canned veggies from the 1970's. Green beans, cauliflower. Of course I had to throw it all away. Saved few empty jars, but some of the canned contents looked a bit moldy so I wasn't ready to open any of the canned stuff. I do get good green beans from the garden each year, but I manage to gobble most of them up fresh...

 

[retromania]

County Home Extension Offices

Each county in South Carolina still has a home extension office and agent, but we're all concerned that they may close due to budget cuts. Anderson County's extension office still answers home canning questions. I remember when I bought my very first pressure cooker (1948 Presto 4qt) at a HUGE flea market down state, I called the extension office to ask about a replacement sealing ring and the firt thing the person said was I needed to bring it in and let them examine it to make sure it was safe. She thought I was talking about a pressure canner with guage. When she found out I was talking about a snall pressure cooker, she directed me to my local Ace hardware for replacement parts. The woman at Ace told me if it was her, she would replace the pressure indicator. It was the kind the doesn't jiggle. A little rod rises up with the increments of weight on it. I love how I can buy a small pot roast and cook it fork tender in the pressure cooker in a short period of time. My problem is storage! I am running out of room for all these pressure cookers and stuff I've got. I am going to have to get rid of some stuff.

 

[tomturbomatic]

Have you put your bed up on a couple of bricks yet and used the space underneath for storage? If not, it is too soon to talk about getting rid of things.

 

[kb0nes]

I was in one of the Mills Fleet Farm stores in the area last weekend and they are closing out the Mirro-Matic 22 quart pressure canners for $67.00/ea, they had several on the shelf.

It was interesting that Mirro changed away from the neat 3-in-one pressure regulator weight, this model had 3 discrete weights. I always thought the 3 pressure weight was a great design.

It seemed as if Fleet Farm was looking to just sell Presto products, this was the only Mirro one they had. I resisted buying one but it seemed like a good deal.

 

[tomturbomatic]

Is Fleet Farm where they grow enemas or large numbers of cars?

 

[westingman123]

*shaking head, grinning*

Tom, did you take an extra "witty pill" today? I hadn't even recovered from the "bed on bricks" comment, and now the above...

 

[kb0nes]

Seems to me an enema farm would require a lot of irrigation...

 

[tomturbomatic]

Well, isn't Minnesota land of 10,000 lakes?

Keith, When I moved to a 1 bedroom condo in 1978, I had to do that for storing boxes of things. On the plus side, it eliminated having to vacuum under the bed.

 

[retromania]

Too funny

Y'all are too funny!!! $67.00 for a 22 qt pressure canner is a good deal for that.

 

[mixguy]

Too funny yet informative

Having read the question I was ready to respond, only to scroll further to see the responses given had a lot more detail than I would have written. Appreciate the humor injected as well! Sure helps brighten a dull day too!

 

[sudsmaster]

One can get the Presto 22 qt canner online for about $67.

I paid about $80 for the Mirro. It was $99 at Orchard Supply Hardware but I had a 20% off coupon (grand opening of remodeled local store).

As I recall, OSH used to sell the Presto, but I held off getting one. I think it was an older design, and better made than the current crop of big Presto canners. I might be wrong, though.

The Magic Seal has a little ding in the sealing area of the lower pot. It would probably still hold pressure, though; I'm going to have to test it at some point soon to find out. Theoretically I could take it to a shop with a big lathe and have the pressure sealing edge turned. I could do it myself but I don't have a lathe that big.

Canning is intriguing but as I recall from making up a few quarts of jam and conserves some years ago, it's also hard work. I've been blanching and freezing tomatoes and peaches since then, mainly because I didn't have a pressure canner.

Speaking of Orchard, time to go to the local store and pick up a replacement timer for the dysfunctions (it eats 9 volt batteries) Melnor sprinkler timer. I have another one that works just fine, though. So must be a defect or short of some sort.

 

[tomturbomatic]

If you think canning is hard work now, imagine it before air conditioning, dishwashers and pressure canners when the jars had to be scrubbed by hand and boiled, often over an open fire in the wash pot to try to kill as many germ spores as possible before they were filled and then the filled jars were boiled for hours for low acid vegetables. A lady I worked with when I was in school told me that since she was one of the younger children, her canning duties were always the scrubbing of the jars (which was done outside to cut down on the number of people in the kitchen) to get them ready for boiling and that's why she hated any mention of canning. Ugh, all of that heat and steam in a hot kitchen or in the outside summer kitchen at the peak of the summer heat is enough to make you droop, but at the time there were few other way to preserve summer produce to keep it edible through the winter. Really poor people would run a thread through apple slices, green beans and maybe some other things and hang them up to dry. Some beans and peas could be shelled and dried, too, but it was very hard work. Everyday life was filled with hard work unless you were wealthy and could afford to hire people to do the hard work before there were appliances to help.