Well for one thing it is far too little water in the canner, especially a 941. So it would take forever to build up a head of steam, enough to fill that volume to the venting point and you would get intermittent bursts of steam as it tries to clear all the air out. Minimum water called for is 3" of water in any PC and in a canner that size, even a bit more would be better. Only 2" could easily burn dry.

Add to that it sounds as if you aren't pre-heating the water first, before inserting the jars. 180 degree water (the recommended starting point, comes up to pressure quickly. Cold water does not yet it will intermittently steam.

But best guess is you are turning the heat down too soon or the heat is falling off for some reason. I know with my propane burner when the pressure in the tank gets low the heat tends to fall off and it isn't always obvious.

Lastly option I can think of is that sometimes the steam column is there but can't be easily seen due to background distortion. I have never had that problem so I can't say how common it is. But others have posted about the difficulty they have experienced and it seems to depend on the light and ambient background colors.

Any possibilities here?

Dave

Well, the canner manual says 2-3" of water. I've always used around 2" even on long runs, like 90 minutes for meat. The water is hot tap water, but not preheated over the burner. I am turning down the heat because the pressure reaches 10 PSI on the gauge. At that point the flame level is about where it would normally be for maintaining it at 10PSI while canning, the vent is blowing like an air compressor, but no steam. My first thought was that the vent was clogged a little which was pressurizing the canner and limiting the energy I could put into it. I checked it, ran a cleaning rod through it, and it is clear.

It's not a problem of perception. It's pretty obvious when it's venting steam and when it is not.

The only other explanation I can think of is loss of steam somewhere else around the canner but you already said that isn't happening.

So if this has worked for you in the past then there has to be something different this time and if all aspects of the canner are the same - no, leaks, open exhaust, lid on correctly,etc. then it has to be something in the heat source, right?

Something you said caught my attention tho in your last post: " the pressure reaches 10 PSI on the gauge".

The gauge is actually reading 10 lbs. before the weight is on? In other words since the weight doesn't go on until after the 10 mins of venting and and you aren't seeing the venting so the weight isn't yet on and the pressure gauge begins to rise only after the weight is on, how can the pressure gauge read 10 lbs. with the weight off? 2-3 lbs ok, but not 10. That would indicate it is the gauge that is faulty.

Follow me?

Dave

Yes, the gauge reads 10 PSI before the weight is on. You can put enough energy into the canner to do that. There has to be pressure for it to vent, whether it's 1 PSI or 10 PSI. The gauge is not faulty. I can put the weight on to regulate to 10 PSI and the weight pops off at 11-12 PSI. I haven't really changed my methods any. I put a moderate flame underneath until it is venting steam and fully exhausted, I put the weight on and lower the heat to maintain 10 PSI. Normally it would steam before it reached 10 PSI, but with enough energy it can get there without the weight on. Perhaps I was heating it too quickly... We're doing tomato sauce today. We'll see if the hot pack changes anything versus the cold whole tomatoes.

<Yes, the gauge reads 10 PSI before the weight is on. You can put enough energy into the canner to do that. There has to be pressure for it to vent, whether it's 1 PSI or 10 PSI. >

Sorry to disagree but not with a normal pressure canner in good working order. It simply isn't possible. All tested and approved models, including All American, have been extensively tested by USDA and by the manufacturers in both venting and non-venting mode. And any fully functioning canner with the exhaust vent open will boil dry before it will reach more than 5 lbs. And it will definitely do that with only 2" of water in it. It is a safety margin built into the canners.

So if your canner is going up to 10 lbs with the exhaust vent still open then something is wrong with it. Most likely the exhaust vent is at least partially plugged whether visible or not and easily so if you have hard water as lime builds up in the vent pipe. OR the gauge is malfunctioning.

I have a 915 and a 941 as well as several other models of canners and have used them extensively for many years . The 941 will readily exhaust a full head of steam well before reaching 5 lbs. on the gauge - normally it is at about 3 lbs. And when the weight is then placed on the vent pipe it takes an additional several minutes to rise up to 10 lbs and move the weight.

If you contact the manufacturer they will confirm that for you.

Dave

That does come back to my original theory of the vent being restricted, but I still think with a large enough burner that you can dump enough energy into it to drive the gas expansion beyond what the orifice can handle, but you'd expect steam...

I really eyeballed the vent and the bore is nice and shiny. Didn't get to canning sauce today. It's still reducing on the stove and I just realized I'm out of propane. Need to run a line from the two 500 gallon tanks out between the barns...

I am no expert on pressure canning (I just started this year), but Dave is right, 10 psi is full pressure for most recipes. My canner is at zero without the weight. I would bet anything your gauge is broken.

I played around with it this morning with just some water in the bottom. I checked the gauge against the weight and it is working fine. The weight popped off at 11 and 15 lbs on the gauge. With my big banjo burner I can easily drive it 10 or 15 PSI without a weight on. I think it has come down to a matter of perception. When it was venting heavily I eyeballed the stream coming out of the vent. I saw a very narrow jet of steam, but it wasn't condensing into a plume above the vent, only very intermittently. If I disturbed the stream with the tip of a screwdriver I could make it condense into a plume of steam which lasted several seconds before disappearing again. It might have something to do with the oppressive humidity we've been having here. It has been around 70-90% relative humidity here the past week.

I asked the same question of the company and they responded this morning saying that as long as it vents for the required period of time it will be fine.

< With my big banjo burner I can easily drive it 10 or 15 PSI without a weight on. >

So you are running much higher BTUs than the 12,000 max BTUs recommended by the manufacturers to avoid damage to the canners. Banjo Burners list 210,000 BTUs. Good luck with that. I already destroyed one canner with less than 25,000. But glad it turned out to be a steam perception problem after all.

Dave

That recommendation originates with thin-walled, stove top canners. This canner is a 40 lb chunk of aluminum with up to 60 lbs of liquid in it. The burner is listed at 210K btus, but that is way beyond the vaporization rate of a 20# cylinder. At full bore, which is quite a roar, it might reach 80K, on a hot day, before the bottle freezes over. Obviously it is adjustable. In this case a needle valve can adjust it down to a wisp of a flame. I've used it a hundred times in this manner without a problem.

New tank of gas, problem solved?

I have a 941 and had the same problem as well. Ive realized turning the heat down from very high to just a moderate flame does the trick. Turn the heat down, youll notice and instant change in the steam. Im not sure why but it works.