It is called siphoning when pressure canning (lots of discussions here about it) as the liquid is sucked out of the jars due to fluctuations in the pressure.

IF the food was properly processed at the proper pressure for the full amount of time and using the proper venting and cool down procedures then the food is safe to eat but the food above the liquid will darken and discolor and need to be pitched after opening.

Sorry for all the qualifications but that is a a lot of siphoning to have happened and it indicates there was some potentially serious problems during the processing. Either the jars were over-packed with solids and not enough liquids or the pressure had to have frequently fluctuated up and down during the processing for it to happen to that degree.

A small liquid loss is acceptable but that much would cause me some concern. I'd probably stick those jars in the fridge and use ASAP rather than shelf-store.

JMO

Dave..

Forgot to specify something, when I said "everything else was done according to this recipe" I meant I skipped one step, the letting it cool. When the time was done I just removed the weight from the pressure cooker. I realized my error after removing the jars.

That will do it. Forced cool down leads to big siphoning and it also leaves air trapped in the jars. If you want shelf storage for the jars and since it won't make much difference to the texture or flavor with cooked greens I'd refill the jars to the 1" headspace with boiling water, put on new lids and reprocess them.

Your choice.

Dave

PS: for future reference use instructions from that source with care. Some do not meet current guidelines. NCHFP has current instructions for everything.

These jars have already been sitting out since last night (wasn't able to ask earlier). Is it still safe to reprocess?

Oooh! Another Southeast Texan!!! :-)

I've been canning a few years now, yet had a siphoning problem this weekend with my greens, too. I have the 23 qt Presto, so I can double deck the jars.

First batch, 14 pints of kale. Was surprised to see the jars had lost quite a bit of liquid. Absolutely followed instructions to the letter. I used So Easy to Preserve for recipe and instructions. I am positive I didn't overpack and removed air bubbles. Kale was prepared according to instructions. Vented 10 minutes, processed for 70 minutes after coming up to pressure. Cooled down 1 hr 15 minutes, checked weight and gauge for pressure, then removed weight, waited another 10 minutes, removed lid and jars. During processing, the weight seemed to be rocking a bit too vigorously, so I did make an adjustment, but not much.

Second batch, this time collard greens. Same prep, same instructions. Kept temp a bit lower to start with and brought up to pressure a little slower. Again double decked and followed the instructions absolutely to the letter. Even though the temp was lower, I did adjusted the heat only once due to the vigorous rocking of the weight, but it was a very slight change. Followed proper processing and cool down procedures. Still had substantial siphoning.

There are a couple of things I've been pondering over the cause of the siphoning:

I have always tightened rings only very lightly, staying with "finger tight" but I had come to believe I was leaving them a bit too loose, and tightened them a bit more than usual...but still, I believe, only "finger tight."

I don't usually process in double stacked loads, but know my canner is designed for it, and I have a proper rack between the two levels. Jars were not crowded, had a free flow of water around them.

Weight rocked pretty vigorously...water seemed to be boiling pretty hard, but I didn't want to adjust temps much because I knew it could cause siphoning.

I have a strong comfort level these were properly processed, but was really surprised it happened in both batches to the extent it did.

Jill

These jars have already been sitting out since last night (wasn't able to ask earlier). Is it still safe to reprocess?

You can reprocess within 24 hours. After that it's fridge or freeze. That is the guideline. Personally I have pushed the 24 hr. envelope by a couple more hours. Your choice.

Jill - the rings causing siphoning may show up in a couple of jars but usually not the whole batch. Over-packing with greens is very easy to do because they will swell and absorb some of the liquid. So it's a fairly common cause of siphoning. But heat adjustment is by far the most common cause.

What is a "slight adjustment" in the heat to one person is usually still too big an adjustment. :) On many electric coil stoves anything more than down 1/4 of the distance to the next lower number is too much. Even the on-off cycling of glass top burners can cause siphoning. Better to just let them over-jiggle and ignore the gauge reading than to try to adjust heat.

Siphoning seems to be the most common for those who use a PC with a gauge or one with a gauge and weight since they just can't make themselves ignore the gauge.

Dave

Dave, thanks for the follow-up. Since I had siphoning in the entire batch...both batches, I will revisit all steps when I process more greens.

Although I didn't think I overpacked the greens, especially since after processing the greens still fill no more than 2/3 to 3/4 of the jar, I will pay closer attention to that.

Your description of the adjustments on an electric coil stove helps me.

The combo of the gauge and weight aren't an issue for me because I only listen to the weight. I do use the gauge when I first put the weight on, just to see the progress of coming up to pressure.

Thanks again...always a learning experience, and always appreciate the voice of experience!

Jill