My questions are: 1) At what point do you start timing the venting? 2) Does the rocker have to rock, or can you just keep the pressure at 11 and start the timing there regardless of any rocking?...

First, for reasons that I stated in the other venting post, I do not think "venting" is needed. Granted I am a pariah on this.

But with the beginning of the pressure cooking event, a rather constant pressure inside the vessel is essential for good results. If steam is not fugative from the canner during the entire process, something is wrong. Steam MUST be expelled at all times (assuming that you are canning stuff). If not, lacking that steam-venting condition promotes poor results ranging from dome-sealing failure to expulsion of product from the jars.

Keep in mind that the gage indication is dependent upon the effective weight on the vent, assuming that both are properly functioning.

So ya gotta get the thing rocking and venting steam and keep the burner heat up to keep it that way the whole time. Once you get a good and stable "rock" on the vent, DO NOT MESS with the temp of the cooking surface. I think that some of your problems stem from the possibility that you are over-adjusting the temp controls of your cook-top. Once the weighted vent starts to blow off steam, do not reduce heat abruptly. Just in small steps until you achieve a gentle rock of the vent's weight. You must realize that there is a lot of latent heat capacity in a large pressure canner and it takes time for it not only lose heat but to gain it as well.

Reg

Venting is needed as you will not have an accurate pressure reading unless you get rid of the air first.
Air trapped in a canner lowers the temperature obtained at 5,10, or 15 pounds of pressure and results in under processing. To be safe, all types of pressure canners must be vented 10 minutes before they are pressurized.
You get a good steady flow of steam before you set the timer for the 10 min.
Is your dial gauge accurate ? Did you have it tested before you used it within the last year ? They need to be tested every year.
The counterweight doesn't rock on the dial gauge during regular processing at 11 lb. pressure. It should rock at 15 lb.
As long as your pressure never dropped below the 11 lb. mark at any time,( assuming you know your gauge is right) it is fine. If at any time it drops below the required pressure you must start the whole processing time over.
You use 2-3 inches of water in the canner. If the 3 quarts doesn't come up that far before putting the jars in, it is not enough water.

Hi marti - Yes, when it is visible and not just felt. I have the Presto too and when you can see a steady column of steam - I mean it looks like a little mini-locomotive blowing its gasket ;) - start your 10 mins. then. After 10 mins. put on your weight.

As to the # of pounds...keep in mind that dial gauges unless tested annually are not considered safe measurements. You can use it but allow extra pounds, say 12, and even higher will not hurt anything. You say "the pressure climbed to 15 and the rocker never rocked" then you weren't really at 15 lbs. and your gauge definitely needs to be tested. Assuming all else is ok with the canner and that you are not at high altitude then the guage will always rock at 15 lbs.

This is why so many of us have gone to the 3 piece weight set that Presto offers. That way you can use the required weight, ignore the gauge, and when the weight jiggles you are where you want to be weight wise. Start your timing for processing then.

You will have to adjust the burner heat - decrease it in very small increments as Reg said above. On my electric stove it doesn't take much to keep a steady slow rocking going...just down from 10 to about 8 on the dial in 1/2 step increments over a couple of minutes - with electric burners you don't get immediate response as you do with gas. When I use it on the gas burner it is a bit harder to adjust - faster response but smaller increments required. Just experiment a bit with very small changes and you'll get the hang of it.
;)

Hope this answers your questions, if not, please let us know.

Dave

Before I posted, I did a search on venting and found a post by johnb, about the 2 inches. This time (I've got it going again now) I put 2 inches in even though that is 4 quarts, not 3. I had the gauge checked last summer & it was fine. Last summer, the rocker rocked at 11 pounds when I canned veggies.

and she said it best. ;)

Dave

Venting is needed as you will not have an accurate pressure reading unless you get rid of the air first.
Air trapped in a canner lowers the temperature obtained at 5,10, or 15 pounds of pressure and results in under processing. To be safe, all types of pressure canners must be vented 10 minutes before they are pressurized.

No and No,

Pressure and temp are the same but air does not have the same transfer of heat as steam or water of the same temp have.

So it takes longer for the jars' contents to heat in air that it does in steam at the same temp. And longer for the jars' contents to heat in steam than in water at the same temp. The TEMP is the same... the transfer of heat is different in these mediums. Canning tomato product jars in an oven at 245 °F would be fine but would be messy and would require more time and energy. But even exposed to air in an oven, the contents of the jars would eventually reach the temp of the ambient conditions therein. How can it be otherwise ?

In aqueous fashion, sitting in a sauna or in a steam bath or in a water bath all at same temp. Which of the three do you think would heat you faster ?

This about the effective transfer of heat, not about pressure. Once that heat has been transfered, it only needs to be maintained in canning.

Reg

Maybe we should have a 'venting' forum.. Or at least one that can deal with all the somewhat redundent 'pressure canning' questions...?

I had the gauge checked last summer & it was fine. Last summer, the rocker rocked at 11 pounds when I canned veggies.

Then either a) the test on the gauge was incorrect, b) your pressure cooker is too small for canning, or c) you are using a 10 lb. weight rather than the standard 15.

What capacity is your Presto canner and what # pounds is marked on your weight? The only time I have seen any weight rock at less than 15 lbs. was when using my small pressure cooker (not all pressure cooker can be used for canning) that has a 10 lb. weight on it, or when I use my 5 or 10 lb. weight on my big canner. So what size is your weight?

___________

Reg - we understand your technical objections to the published guidelines but please recognize that they ARE the tested, published, and accepted SAFE standards done by professional testing laboratories.

No matter your personal opinion of those labs or those standards, you aren't going to change them. Take it up with the USDA. Meanwhile all you do confuse those new to the process of pressure canning - which already has enough misinformation and confusion to deal with.

If you elect to not follow those standards, that is your choice of course, but to encourage the new and uninformed to do so is dangerous. Let them first learn the safe, tested, and accepted way to do it. Thanks.

Dave

I agree with you, Dave !!! I am trying to teach the new people how to do things "by the book" so they will be 100 percent confident their foods are safe. Also, they will be able to see the methods and information online or in some tested books, too. I know most people seem to want to have something written and tangible to work from in the kitchen.
Yes, Reg, I am an "extension person". I am trained and answer food safety/presrvation questions at my local extension office.
Marti, the counterweight should not rock at 11 lb. of pressure. I am thinking the gauge is bad. It should rock at 15 lb. What the dial gauge canners have is called a "counterweight". It is used to allow the pressure to build and to hold it in the canner. It is not the same as the regular weight set you can order from Presto. You can order the set, then use the 10 lb. or 15 lb., depending upon your altitude. You use it as a weighted gauge canner instead of using the dial. It is fine to convert it over. I checked with both Elizabeth Andress, the lady who wrote the USDA guides, from University of Georgia, plus contacted Presto twice, as well.
I just got my set recently and will use them, even though I can test my own gauges.
It is getting harder to do the testing due to liability. We have to have people sign waivers saying they will not hold us responsible. We are only able to still test because we have permission from the State Attorney General. Some states don't test any longer.
Marti, I am assuming by your post that you have the dial gague canner with both the dial and the counterweight. I know Presto makes a new weighted gauge one, that you buy at Walmart. It is either 16 or 18 quart sized, I don't remember which.

I called my county extension office & the next county and neither of them test anymore, because there is a piece of equipment now required that they don't have. I was told to contact Presto & send my gauge to them for testing. I don't know about that. If it was fine the last time I had it tested, and if it is now incorrect, and if some jostling in my cabinet messed it up, I don't think shipping would be good for it.

I have a Presto 23 qt Canner. There is no weight of any kind on the pressure regulator, just a few numbers which I assume is the model #. I assume it is a 10 lb, but don't know for sure. It's the one that came with the canner 10 years ago & is the same as my 30 year old Presto pressure cooker.

It has always started rocking at 11 pounds until this week. The only thing I couldn't remember if I did the same was the venting.

Marti,
Well, if you send it to Presto, and I know they do test them, you still won't know if it is accurate for sure when you get it back. They get jostled around during shipping.
My suggestion is that you buy the three piece weight set and use the ones for 10 lb. pressure.
What you have isn't a real weight, but a counterweight. Technically, it should rock at 15 lb. pressure, but is not meant for relying upon for a pressure reading. It is just to allow pressure to build in the canner and to hold the pressure in the canner.
If you will get the weight set, then you will leave the dial gauge on, but rely upon the weights. You will use it as a weighted gauge canner.
Many people are having to do this because they can't get their gauges tested.
In order to test at the extension offices, they must have the new test unit. The old ones are not allowed to be used any longer.
I also have the 23 quart Presto.

What you have isn't a real weight, but a counterweight. Technically, it should rock at 15 lb. pressure, but is not meant for relying upon for a pressure reading...

I have a 5-10-15 weighted pressure mechanism. So I was not familiar with "dial gauge" pressure "regulation" (actually not regulation, but displaying). I delved into it a bit and it is rather simple. And also explains why steam venting is needed in using this type of method with this type of vessel. The "counterweight" is a weight that is really a safety device to control an over-pressure condition inside the vessel. And is designed to commence releasing gaseous contents of the vessel at a certain pressure (or a narrow range of pressures), probably normally corresponding to the pressure that a "15# psi" weight would control by becoming unseated. Just a safety device... so it and the vent orifice do not need to be precisely calibrated so long as it is does not vent lower than 15 and higher than maybe 17 psi.

The only real advantage (other than a double check... if you also have a weighted gauge) of this arrangement over the "5-10-15 weighted gauge" is that it allows a fine-tuning of the effective "weight" (and thus pressure for different altitudes) in increments between the 5-15 range. But this must be accomplished by finely adjusting the heat applied to the vessel and monitoring the gauge (that messing around with the heat, I think, is the primary cause of the problem tanyak is having with her AA pressure canner). Sure, if you do that and the thing does not vent (because pressure has not overcome the "counterweight"), nothing will have escaped, including air, and that is no good.

(To me the monitoring of the thing would be a pain... I just get mine venting [ under pressure ] and adjust heat a wee bit until I am satisfied that I have a sustainable (but not a rapid) release of steam, set timer, and turn off cooktop after time has expired).

Moreover, this also explains why the gauge should be checked annually. Because if you are normally operating the vessel at pressures below the blow-off, the gauge is the only indicator of pressure. And if it is wrong by a significant amount, you could end up with an internal vessel temp that is not safe.

This type of canner (one that requires a pressure dial as the only indictator of pressure [ other than the unseating of a safety device ] ) I would buy.

Reg

Linda Lou, just to make absolutely sure, are you saying that the standard 5-10-15 weight set sold by Presto can be used reliably on the 23-quart dial-gauge canner, in lieu of testing the gauge? This would require that the vent hole be exactly the same size as on the weighted-gauge canner...are the vents really the same?

How do I find the weights? They aren't listed under the 23-quart model.

There are one or two of the new testers in Virginia so last year I drove out to a rural area to get mine tested. It was worth it because I bought some great produce while I was out there.

Melissa

Linda Lou, just to make absolutely sure, are you saying that the standard 5-10-15 weight set sold by Presto can be used reliably on the 23-quart dial-gauge canner, in lieu of testing the gauge?...

(Parenthetically, the last line of my last post should have indicated that I would NOT buy a "dial gauge" pressure canner).

Now I do not know what LL may think about your question, but I do. And it is this:

If the manufacturer does not recommend that their 5-10-15 weight set or their 5-10-15 "weighted gauge" (functionally really the same things in different packages, assuming that they have them for certain models) be used on your pressure canner model, do not even consider doing it. Because if the manufacturer indicates that it is a no-go, that means that it probably will not even fit, let alone been tested for proper function on that particular model.

If Presto has such a part that was designed for your canner, good. If not, forget it.

To me, some people think of this home "pressure canning" stuff as an activity that is steeped in mystery and practiced to perfection only by those possessed with an arcane and voodoo-like pressure canning ability. It ain't so.

Reg

Melva, that is what I am saying. It is safe to buy the three piece set and use on the 23 quart Presto.
I emailed Elizabeth Andress, the lady who wrote the USDA guides and she also is head of the University of Georgia where the National Center For Home Food Preservation is. She is the "expert" by far. She said it was a fine idea to recommend. She sees no problem with it. I also contacted Presto both via email and by phone. They even told me the part number for the weight set and said it was fine to use on the canner. I did research it before I started giving the recommendation.
So, you can go to any of the sites that sell Presto parts and order the three piece weight set. It fits perfectly on the stem of mine, at least.
If you check out this link, you will see, it even gives the model numbers of canners the weight will fit. It doesn't say "cooker" but "canner".

One other note, even the so called "self venting " canners need to be vented for the 10 min.
From WSU extension :
My pressure canner is the self-venting type. Does that mean it still needs to be vented 10 minutes before closing the vent?
All pressure canners, including Âself-venting pressure canners, do need to be vented 10 minutes before the pressure is allowed to rise. This venting time is a way to be certain that all air is removed from the pressure canner.

Research has shown that under some conditions (particularly with the raw-packed foods) all air may not be removed from self-venting pressure canners. If there is air in the pressure canner, the temperature is much lower than if the canner contains only water and steam.

http://clark.wsu.edu/family/FAQs.html#venting

Here is a link that might be useful: Presto weights.

Linda Lou, I trust your advice and know your #1 priority is safety. I agree that someone new to canning might get a little confused and bewildered by this thread. I learned something here, though, about the weights and so forth. I had thought that my canner was off because it didn't start to rock until 15 lbs....;))) Sometimes I think that canning is like a lot of things, where we have many "advancements" or the like when people have done this for decades. Like you said in a past post, in years past, people boiled their canned goods before eating which probably helped more than a little. I see where Reg is coming from but it's a bit confusing and I absolutely want a SAFE product that I have no qualms with feeding to my family. If I have to think too much, re: pounds of pressure vs. air/water/steam, various weights, I think I would be unlikely to process anything. I want safe, but not rocket science. Lori, just a humble opinion ;)

Lori,
I am glad it is making more sense to you. I am someone who just wants things to work. I am not always so adamant I know why, just that it does !
You are right, things have changed in the field of home preserving. What may have seemed safe then is not always the case now. There have been advancements in the science of canning, just like in medicine and other fields.
I was reading a book recently and how it was discussing some of the old medical procedures. It would scare the hair right off of us nowdays !
I figure what is a few extra minutes to do something when canning and be 100 percent sure you and your family will be safe. We all want food that tastes good, but we also want it safe to eat. Goodness, most every week I read about some recall of foods from the store with ecoli, botulism, salmonlella, or something. Makes me afraid to eat the stuff. Kroger just recalled some 3 bean salad from some of their stores. I think it was deli food.
Keep on canning your own, it has got to be better and safer than that.
Personally, I think more and more people are going to be needing safe food preservation information as time goes on.
Happy Canning !

Thank you Linda Lou, I think I'll buy that 3 piece set. Does it come with instructions? If not how do you know how to put them together?

I don't can often enough to remember exactly how I did things the previous summer. Wish I could watch someone like you do it.

I did search youtube, & there are several videos, none of them showing the pressure canner venting, or what it looks like when they come up to the right pressure. Wish someone like you would do that for us. ;)

Marti8a,
It doesn't come with instructions that I know of, but it is simple. One ring is for 5 lb. Add another ring, then you have 10 lb.. All three together is 15 lb.
It is easy to use.
You mean you think I should be a movie star ? LOL !
Our extension educator has a really old one of her and some other lady doing water bath canning. Not one on pressure canning that I have seen, either. Hmm, may be a good idea.
I have often teased about me doing a traveling canning show.

Linda Lou, thanks a lot for clarifying. I think I will try to get my gauge tested again this year, but if it's too difficult, I'll buy those...I'm sure I'll end up buying them at some point when they won't test anymore.

Reg, Presto said it was ok. That's what I was asking. I notice that the vent pipe has the same part number on their weighted-gauge and dial-gauge canner, so my question about having the same size hole to build the same pressure based on the weight has been answered.

Thanks!

Melissa

Yes, Linda Lou! I think you should get into the video business now so you'll be a fave when the awards are handed out!

I hope these are readable. Scanning printed pages and keeping them readable at the same time as keeping the size down is something I need to work on. My apologies to those using dial-up.

I could do better by making a .wmv video, but not today.