I don't think you're doing anything wrong. I'd say this is a design flaw of the Mirro. The Presto and All-American weights just drop on.

[Another reason I don't like Mirro.]

I don't know what your model number is, but if it's compatible, change to S-9898 which is a 5-10-15 psi drop-on weight. You can see what I mean by checking the link. I'm not recommending that site. You can get the weight more cheaply elsewhere. It's just a good comparison picture.

Carol

Here is a link that might be useful: Mirro Pressure Cooker Regulators

The flaw is in Mirro's book for their new pressure canners. I called them last year after I tried to do the same thing you did, Jacquef. I suggested they had a lawsuit waiting to happen.

They are supposed to be reprinting their instruction book. You don't have to vent the new mirro...just screw on the weight and turn it on...it will vent automatically. Once they told me that, I like it a lot.

That's interesting and good to know. So you screw on the weight then observe until it's vented a full 10 minutes through the orifice before beginning processing time?

You'd think they'd tell people before someone gets seriously burned. What were they thinking???

Carol

I've only used it a couple of times since I called them, and I didn't time it, but it did vent. It's a whole different noise, but it seemed to work well. I had a Presto, but also had bad gauge karma. When I messed up the threads changing a gauge I went to the Mirro.

We spent a day testing gauges last week...the newer ones were worse than the old. Our Extension tested every new gauge in one of the hardware stores and they were all off...every one. Probably tossed off the truck...what precision instruments??? sighhhh.....

I have the three-piece regulator for my Presto. Funny they listed it as an accessory in the old manuals but now half the time if you call the company they pretend it doesn't exist.

The nice thing is with the three-piece regulator the gauge becomes the backup. In essence, the Presto becomes a weighted gauge rather than a dial gauge canner. It's a way of emulating the All-American setup.

Fortunately, we have an Extension office here in town and they do still test gauges, but those gauges are so chintzy it doesn't take anything to throw them off. I'd rather rely on a machined weight.

One way or another they're all a pain. My original canner was a Presto. After 30+ years the bottom developed stress fractures so I "retired" that one in favor of an All-American. I just picked up another 23-quart Presto at Bimart for $59.99, which is an incredible buy. It'll make a great stand-by canner.

Carol

Here is a link that might be useful: Presto Canner Three-Piece Regulator

Good to know!! I've been doing the "glove-steam-lawsuit waiting to happen" thing for 2-3 years now! Never even thought to call them.
Thanks katiec for letting us Mirro folks know!

Deanna (now in the "no scald" zone)

I have been canning for about 5 years now, and do let he Mirro vent for 10 minutes, but i hve no clue why I need to do this. Please enlighten me.

Peppi

I have two 22 quart Mirro canners and have had them about 30 years. They do not have the type regulator you talk about, just a round weight with the number of pounds of pressure printed on them. I always let mine vent a few minutes before setting the regulator on. Have had no problems. I have done a lot of canning in them.

Sue

Deanna, I didn't know the new ones had been out that long. They really need to get in gear with new instructions!

Peppi, from the Nat'l Center for Home Food Preservation: Errors can occur if: "Air is trapped in the closed canner during the process. Air trapped in a pressure canner lowers the temperature obtained for a given pressure (for example, 10 or 15 pounds pressure) and results in underprocessing. To be safe, USDA recommends that all pressure canners must be vented 10 minutes before they are pressurized."

Of course, that was printed before the new model Mirros came out. The last time I saw our Extension Educator, she was gleefully heading to the phone to call the university and tell them about my call to Mirro. Apparently they said there is no such thing as a self-venting canner.

Sue, I do miss my reliable old beast. Poor old thing just wouldn't hold pressure any more, even with new gasket. I'd used it for at least 25 yrs.

This is really good to know. I hope Mirro uploads those instructions to the internet. On Harvest the issue of venting comes up frequently. This is really going to change things. A lot of people are buying the new Mirro.

Carol

I know this is an old thread but the info in it is not correct. The weight that looks like a round bomb and has to be screwed on is not self venting. It has a retention ring that is for shipping and storage that should be removed for canning. i am attaching photos that show what needs to be removed. The blue arrow points to the bottom of the five pound weight. The red arrow shows the retention ring that should be removed for canning.