mirro matic pressure cooker safety valve factory

Mine is pretty old, so I am not sure how the new ones look. I have a red plastic plug in my lid, and it"s a safety valve. It"s designed to blow before the canner builds up so much pressure it"s dangerous. I"ve never had that happen in a canner, but have in a pressure cooker, and it decorated the ceiling with food. LOLOLOL. But, it worked!

You likely have two little latches on either side of the cooker built into the handles. You can"t even see them unless you kneel down and look at the handles from the side view where they"re engaged. After the cooker builds up enough steam, they"re triggered to drop down from the upper handle section to the lower one into a slot to "lock" the canner shut when it"s under pressure. That"s a safety device to stop people from opening the lid and having steam and hot contents spew out at them. The very, very old canners didn"t have those and serious burns were common when pressure canning because of it. I had a sister in law who was burnt like that when she was a child and helping her mother can.

On my old mirro, until the steam built up to a certain point, even after the weight is over the vent, but before it jiggled, it was/is very common for steam to escape at the points in the handles where those safety locks are. You may be seeing that. Once in a while, the locks drop quickly, but usually not. Until they do..............you are really at risk trying to unscrew the top to reposition it. Steam is hotter than boiling water and can scald instantly.

If the steam and water continue to spew and the safety doesn"t lock, you must turn off the heat and let it cool enough steam won"t escape before you try to reseat the lid and gasket.

I have found it helps to physically stretch the gasket a little (they"re very stiff) and yes, lubricate it before each load. Dry, hard rubber doesn"t make a good seal. I also "snap" the lid firmly when closing the top to start the cooker. I find mine has to be in the perfect position for the safety to work properly, could be it"s "off" a little on the tolerances, or just getting old.

IOW the cookers can be a little touchy and found that this is the nature of that particular beast. Re-read the manual, or maybe even try to find an experienced canner who has one to walk you through it too.

When home canning fills your shelves and appears in daily family meals, you could use a large-capacity pot, like the Mirro 22-Quart Pressure Canner. The large, tall pot lets you safely process more than 25 pounds of beets, potatoes, or other low-acid vegetables in one batch. Bigger can be better if you’re preserving a season’s salmon catch or turning venison or beef into stew meat.

Mirro’s history is a bit more scattered than the other big names in pressure canning, but it’s been around since the early 1900s. It began changing corporate hands in the 1980s, and after several shifts ended up with France’s Groupe SEB, which also owns All-Clad, Tefal, and Imusa. Through it all, little seems to have changed in the canner’s design.

I spent a couple of weeks testing this large-capacity pressure canner and cooker with large and small batches to see how it stacked up against the competition. Here’s what I found.

Mirro’s largest canner has two uses: pressure canning and pressure cooking. Older versions of the user’s manual mentioned using it as a water-bath canner, but my test unit’s booklet (dated September 2019) says to use “a conventional cooking pot” instead.

Like most full-size pressure canners, Mirro’s 22-quart model can hold 7 quart-sized jars, but this canner is so large that you can stack two layers of smaller jars. You’ll pack in the greatest number of regular-mouth ones: 18 pint-sized and 24 half-pint jars. Mirro provides two canning racks to make stacking easy. Set one rack on the pot’s bottom and one between the jar layers.

The canner’s streamlined design is attractively polished outside and functionally matte inside. The pot’s aluminum construction rules it out for induction cooktops, and it has a concave base that won’t work well on glass-top stoves. Given these features and its fully loaded weight, which can top 45 pounds, it makes sense that Mirro would only recommend gas and electric coil heat sources.

The pressure canner comes fully assembled with its operating valves tucked in a small box. Before you start canning or cooking, Mirro recommends running the canner under minimal pressure with just water and baking soda. This treatment didn’t seem to prevent the aluminum interior from darkening, which seemed to be the intent, but it was a great way to give the canner a test run.

The user’s manual is worth reviewing to learn about the canner’s components, but it doesn’t always jibe with U.S. Department of Agriculture guidelines. Jar sizing and processing instructions seem to have been culled from an older or inaccurate source, and they gloss over some details. It’s hard to recommend the model to an entry-level canner without that caveat that you should follow USDA guidelines, rather than Mirro’s manual, to ensure safe processing.

This canner’s key feature is its weighted gauge. Mirro includes three regulators, calling them operating valves, that can be swapped out depending on what you’re canning or cooking. Weighted gauges lock you into broad pressure targets, so you may be processing jars under more pressure than they need to safely seal. The upside is a weighted gauge doesn’t need annual accuracy testing. The company recommends swapping out the gasket annually and having the entire setup checked at an approved service center every 10 years.

The canner tested well when processing beans in mixed batches and sealed all lids when I jarred up soup. It took practice to get a steady regulator jiggle on my gas stove. Setting the pot on a larger burner helped, but at my 3,000-foot elevation, I still had to adjust the burner heat more often than with dial-gauge canners to keep the pressure steady.

It also took a few tries to lock the canner’s lid closed so that it would build pressure. It was easy to over-twist the lid, but perfect top-to-bottom alignment still vented steam through the pressure indicator and handle rim. Turning until the top handle was just slightly forward of the lower one on both sides immediately popped up the pressure indicator once the canner started to steam. This may be a quirk of the specific pot I tested and not all Mirro canners.

Even though Mirro sells this model as a pressure cooker, you’d probably skip this use unless you’re feeding a large, hungry crew. The recipes in an enclosed booklet are all scaled for small pressure cookers, so you’d have to make triple batches and plan to feed 24 to 36 people from this pot.

This large canner typically sells for $100 or less, making it one of the most affordable ways to fill your shelves with home-canned goods. For that price, you get a second rack for double decking and operating valves at three pressure levels, pieces that are sometimes sold as add-ons to other pressure canners. Mirro’s design also requires less maintenance than many pressure canners, cutting down on your costs down the road.

Although it’s less expensive than much of the competition, the canner has more limitations. You’ll want to choose another brand if you have a flat cooktop. If you’re nervous about pressure canning for the first time, you may prefer a model with a dial gauge so that you get more feedback on what’s happening inside the sealed pot.

Mirro’s pressure canner is easy on the budget at initial purchase and over time, but you have some other options that keep you in a similar price range.

Presto 23-Quart Pressure Canner and Cooker:Presto’s 23-Quart Pressure Canner and Cooker (view at Amazon) holds a couple more jars than Mirro’s similarly sized model and doubles as a water-bath canner for jars ranging from half-pints to quarts. It sells for a few more dollars (with a retail price of $109), but needs less frequent gasket replacements. Its dial gauge does need annual testing, which could require shipping it off to Presto.

Presto 16-Quart Pressure Canner and Cooker:To step down in size and save some cupboard space, consider Presto’s 16-Quart Pressure Canner and Cooker (view at Amazon). It’s nearly the same price as Mirro’s larger canner but also works as a water-bath canner for pint-sized and smaller jars. It has the same maintenance needs and costs as Presto’s larger model and can be used on glass cooktops that can handle its 41-pound loaded weight.

The Mirro 22-Quart Pressure Canner has basic looks and features and packs lots of jars inside. Experienced canners at low elevations may love this low-maintenance, weighted-gauge model. Novice canners and anyone living at a high elevation will want to do some research before processing the first batch.

This Mirro pressure canner has VERY mixed reviews. Many people volunteered information from their personal experience. I’ve included their reviews below so you can check it out. Some love it…some not so much.

Photo Credits:Thanks to Sam C. for generously taking photos of his Mirro 22qt canner! He mentioned the canner pictured holds 7 quart jars; you can stack 16 pints (8 per level). He said it also claims you can stack quart jars, but any of the quart jars that they’ve tried have been too tall to stack.

I can not confirm just how many jars the 16- or 22-quart capacity will hold. There is conflicting information out there. Even the Wearever website (the manufacturer of Mirro) does not list the quantities. I’d suggest that you confirm this before you purchase so you know just what you are getting.

It seems like the people who love their Mirro have had their canner for “years.” So it is very possible that the quality has simply gone down and newer canners are not the same as the old ones.

Edit to add: Most of the comments below from owners of the Mirro pressure canner are reporting that it does indeed hold 7 quart jars, but one person did say only 5 quart jars will fit.

For the 16-quart cooker/canner, I can’t seem to confirm just how many jars this cooker/canner will hold either. From reports of users (found below), anywhere from 5-7 quart jars will fit.

The Mirro pressure canner does not come with a pressure gauge. Pressure is measured with weights. This is not a problem! Weights are a standard way of measuring the pressure in a canner. However, for those who prefer a gauge, you might want to look at either the

I’ve not used a Mirro pressure cooker or canner. So I asked around for some reviews from people who actually use it. These are some responses I received.

I noticed that many call this piece of equipment a “cooker” instead of a “canner.” I’d like to remind folks that there is a difference in the two. A canner is larger and will process foods for storage on the shelf. A cooker is smaller and is for cooking dinner.

According to the USDA, a pressure cooker/canner will only work safely for canning if it is at least large enough to hold 4 quart jars. Not 4 quarts of liquid. But 4 quart size jars, upright.

I love my mirro matic canners. I have had one of them for 32 years and it holds 4 qts. The other canner is a mirro also and it holds 7 qts. I have never had issues with them other than replacing overpressure plug. Will probably never use any other brand. Love using the weights.

I bought the Mirro 16 qt canner last summer, and used it for the first time last week. Called customer service, and received very poor information. Was told it would hold 10 pints. I struggled to fit 9 pint jars in it, and one broke during processing. Also, found that the 10# vent wt was not jiggling, moving at all, simply emitting a steady release of steam from the 4 holes in it. If I turned the heat back so it only released steam intermittently, the red safety button on handle would release. After use today, customer service tells me that it is defective, and I must mail it back at my expense for replacement. Never have I had a company refuse to pay shipping for return of a defective product. They refuse to refund money, yet expect me to pay shipping ? I am disappointed with customer service and product.

I have a 22 qt mirro pressure canner and it holds 5 qt jars with 8 pints on top level, or 16 pints total in two layers. Make sure you use the dividing shelf…you cannot stack quarts in this one.

The product is terrible; rust came out to the top vent tube. I followed the limited, poorly written instructions to the best of my uninformed ability. I reread, had my husband read and reread, the instruction. After the first test run, which worked, I load the meals I spent 8 hours preparing for meals. The side handle vent leaked!!! So I shut the canner down, waited an hour, opened it up! I check the relief valve, rest the silicone gasket, replaced the water, reset the jars and started again….That also failed. Before the next attempt his AM, I decided to read these posts… So the only thing I tried different was a drop of oil on the gasket. FAIL.

I called the 800 number and was told to take the product back; they didn’t know what was wrong…I WILL BE RETURNING THIS PRODUCT…I WASTED A DAY’S WORK AND TONS OF GOOD VEGGIES. NO MIRRO FOR ME!

I finally got my weight to hiss and jiggle to perfection only after ripping my hair out, having a temper tantrum, and putting the weight on properly! The directions were not clear. Follow all directions as usual. When you place the weight on the stem, be sure to push it all the way down. If there is enough pressure in the tank, the weight will jiggle. I hope this is helpful.

We recently bought a new 22 qt. mirror pressure canner. The instructions are very poor compared to the old cooker. Old instructions had what weight to use for each cooker, jar sizes and type of food. The new one has very little instructions for any canned food. We are using the old instruction book. The weight jiggler (5 psi) on the new cooker fell apart on the second time we used it this year.

Just got off the phone from Mirro. I have a 16 Qt model #92116. I was very frustrated with my jiggler not jiggling as per instructions. She said they are going to be updating the manual.

Not sure why people are having problems with their Mirro canners. We have a 16 quart among other brands, and it will hold 7 quart. You MUST heat the canner up, as the instructions say, until there is a constant hissing BEFORE you put the weight on. It will then need to be adjusted so it jiggles 3 to 4 times a minute. Yes, it jiggles.

Those who are having to bang, hit, bop or whatever to “seat” the weight should purchase a new vent stem and/or weight. Mirro made some changes in the 70s and 80s so make sure you are buying the correct gasket based on the model and YEAR it was manufactured. A model number may have two different sizes and thicknesses based on the YEAR of manufacture.

I have a Mirro 8 quart canner M-0598-ll dated 5/83 and ordered a new gasket. I was sent a S-9892 gasket, which isn’t thick enough to seal the lid and steam escapes all around the lid. Lid fits on very loose and the S-9892 gasket is about 3/16″ thick and I need one about 1/4″ thick to take up the slack. The diameter is fine, the thickness of the replacement gasket is not.

I have called or emailed several places including PressureCookersOutlet, among many others, and they all say, “Sorry, we only have the S-9892 gasket for your model.” Well…it does not fit! Canner is in good condition and not compromised in any way. It is just that the aftermarket gasket is definitely too thin.

I have used Mirro canners for 40 years. Love them. Replacement parts are easy to get even after 40 years. They never fail. Foods always are preserved. You can’t go wrong with a Mirro.

The regulator weights provided with my #92122 Mirro canner do not jiggle. They only hiss and (sometimes) spin. The instruction book was not updated to reflect this change of design from the older Mirros, which had jiggling regulators. The non-jiggling weights are far too ambiguous. I was never sure whether the pressure was correct unless I constantly watched it.

I have owned and used my 22 quart Mirro pressure canner since 1982. I love the weighted gauge and the instruction booklet gives great instructions if read carefully. The book says after venting 10 minutes, add weight. When it starts to jiggle constantly, turn temperature down so that it jiggles 3 or 4 times a minute.

I found thru another site that Mirro re-did their weights approx. a year ago but didn’t upgrade their manual. The new weights only hiss instead of jiggling. Very hard to use especially if you’re hearing impaired. Does anyone know if you can use Presto weights that visibly jiggle on a Mirro canner? This hissing is for the birds. I’m only guessing at things now.

You can tell the age of your Mirro by looking on the bottom – there should be a fraction such as a 3 on top and an 81 on the bottom. That means it was made in March of 1981. That will help you determine which gasket to buy. There is only one source of gaskets for the older Mirro canners that I could find and that is: PressureCookerOutlet (Red Hill General Store) – call and ask for gasket 3440 for canners built before ’83.

I had read something by someone saying they would never use a Mirro. Can’t understand for the life of me why. Easy-peasy. Just twist the lid shut, no fiddling around with all those wing nuts, wait for it to evacuate, set the jiggler and you’re off to the races!

I have used a Mirro pressure canner for 40 years. You do need to keep an extra gasket on hand but have had years of wonderful service from it. They are basically good for life. The basket rusts after a few years’ use, but you can purchase a new one, but it is fine to use like it is. Happy canning–nothing better!!!!

This is my first pressure canner, and I agree that the manual is incomplete. It gives you all the warnings but doesn’t actually tell you how to use it.

I have owned my Mirro 16 quart for 23 years. I have primarily used it for canning quarts, of which it holds seven. I have replaced the rubber gasket only once in this time, and though I bought extra safety pop off valves, I have never had to use one.

The only pitfall I have found is that the Mirro cannot be used on flat top ranges (it is concave and won’t contact the burner in the middle) and the Presto claims that it can (flat bottom).

I’ve edited my article because the feedback I’m getting is conflicting with the information posted online. I don’t have a Mirro myself so I can’t confirm it, but I believe the 22 quart is large enough.

I’d recommend getting a pressure canner that will hold at least 7 quart jars. That is a standard size. Presto and All American also make canners that are tall enough to stack 2 layers of jars. I like stacking pints so that is what I have.

All American pressure canners set the standard for being heavy duty and easy to use. Made in the U.S.A.! Pros and cons to help you make the right choice!