Pressure canning and losing liquid.

by Reggie

I am canning green beans and chard in an American Pressure canner. I am using Ball screw on rings with new covers every time. I leave one inch head space. I tighten the cover down with modest torque on the ring.

Liquid escapes from the jar into the canner every time. Is this normal? As an engineer (retired) I don't see how the pressure inside the jar can be greater than the pressure in the canner. Is this a head space issue?


Edit to add: I've received this question so many times I built another page explaining the reasons you might be loosing liquid and how to avoid it.

Click here for more details on Liquid Loss in Home Canning

Hi Reggie, It sounds as if you are doing things right.

I've had others question why they loose liquid too. What happens is that as the food is boiling under pressure the contents of the jar expand. Then as it cools the lids are sucked down and a vacuum is formed.

It is common for some liquid to seep out into the water. You don't want too much liquid to boil out however.

When you open the lid to the canner the air will cool very quickly... much quicker than the jars will. This is when more siphoning may happen.

If you are loosing too much liquid you might be taking your jars out of the canner too soon. Be sure and let the canner cool down naturally. Don't try to speed it up by running cool water over it or anything.

When the canner pressure is back at zero. Take off the lid but let the jars set for about 5 minutes. Then take them out of the pressure canner.

I will sometimes just open the lid but leave it set on the canner cocked off to the side. (be careful of the steam it will burn your face or fingers!)

This will allow the jars to cool slower and the contents will not push out of the jars as much.

And this is coming from a very un-engineering type person! :0) So I hope it makes sense the way I explained it.


Comments for Pressure canning and losing liquid.

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Aug 14, 2011
cans alot
by: pat

2011 canning season first time ever loosing liquid from my blueberrys. Canned for 20 years.

Called ball (they own kerr also) they sent me e-mail with everything I am doing. The first person told me they change to teflon.

The second person when I called back again said they just changed the color from gold to silver. It has got to be the lids am changing to mason asap. Someone help!!

Aug 22, 2011
Loosing Liquid
by: PAW


Aug 27, 2011
BALL lids
by: Anonymous

I have canned for 30 years and NEVER have had failed lids. I too bought "BALL" lids and lost alot of hard, hard work. From growing to picking and canning them. I am very disappointed in "Ball" brand lids. I'm going back to Mason.

Aug 30, 2011
lids failing to seal
by: Anonymous

lids will fail to seal if you do the following:

Put the bands on too tight. Venting cannot take place properly and will cause sealing failure. Only finger-tip snug at first resistance is needed.

If the temperature of the canner flucuates too much due to canner malfunction, turning the burner up and down, or cooking on glass top/ceramic stoves (temps flucuate too much), propane stoves, grills, outdoor camp stoves, turkey fryers and the like.

Make sure to SIMMER not BOIL the lids for at least 10 minutes in water.

do not try to rush the cooling process of the jars. Wait 5-10 minutes before removing them from canner and sitting on a towel on the table in a place where they will continue to vent for up to 24 hours to seal properly.

Just because someone says they have been canning for (fill in the years, 20, 30, 40, plus) doesn't mean they are doing it properly. Call your local home/cooperative extension office for new USDA guidelines for safety in canning. Any recipes before 1992 are not considered safe by these standars.

Do not use OPEN KETTLE method of putting food in jars and expecting lids to seal without processing the jars in hot water bath or steam pressure canner. Not safe and may not vent properly to seal.

This coming from BALL/KERR/GOLDEN HARVEST/USDA Food safety guidelines in canning.

Sep 12, 2011
Yikes, ended up with 2 inch headspace
by: BarbJ

I just canned tomatoes in the pressure cooker for the first time using your instructions, when I was done I realized that I packed the jars while they were cold, or room temp. I lost quite a lot of liquid from each jar, I have a head space of about 2 inches in each jar. I did maintain the 10 pounds pressure for 25 minutes. I did leave the pressure cooker cool on it own for quite a while so I didn't leave it set for 2 minutes after I took the pressure gauge off.

I have noticed that when I hot pack, I don't seem to lose the headspace.

Thank you for this web site, I love reading all the canning info.

Hi Barb, If you leave the jars sit in the canner for a few minutes after taking the weights off it does help.

And yes you are correct in your observation, a hot pack will end up with less headspace than a cold pack.

I've also noticed that the pressure canner leaves more headspace than the waterbath. So it really is up to your choice. I like the pressure canner because it takes less time than the waterbath. (total time heating up the canner plus processing). Even though I do end up with more headspace... that doesn't bother me.

Sep 16, 2011
Losing liquid
by: Don in Colorado

I just done a couple batches of corn and they too lost most of their liquid?? They sealed fine and I followed directions exact?? I,m at 4600' so I had to go to 15# cap?? I canned for years in Penn. and never had this problem?? They sealed so I suppose they are still good to eat just not much liquid?? Any advise or help greatly appr.... Thanks and happy canning!! :)

Apr 19, 2012
lids and rings poping off
by: Anonymous

I have been canning for a while now without any problems. This past week while canning I had two lids and rings come completely off during the canning process. This happened in two diffent canning processes. The funny thing is the jars where in perfect shape with the correct amount of water. Did anyone else ever have this happen to them? Does anyone have an answer to what happened?

Jul 05, 2012
Any help is much appreciated : )
by: Patty Ann

First time canner, I tried mushrooms, apples, corn,and carrots. Everything floated,except for the corn which turned a darker color.

I recently read online somewhere that the weights on top of the pressure canner should only rock about 1 to 2 times per minute. I am beginning to think that may be true. Wish I had read that before I started canning anything.

Now I find out that over 'cooking' the corn 'carmelizes' the sugar. Mine actually tasted burned. When I canned, I had followed the direction booklet that came in the box. It said the weights should "gently rock." Apparently, I had the temperature way to high as the weight was moving vigorously.

The directions (Presto) specifically said 'rock gently.' So far I have only wasted my time and some money since everything was on sale. But I really would like to learn how to do this.

Has anyone else heard that the weights should only shake 1 to 2 times per minute? I am afraid to put the time in again if it is not going to produce better results. How much practice should it take to get this right?

Jul 30, 2012
i am an engineer too! :)
by: Bob

Besides cooling too fast, if you do not put enough water in the canner to start it will cause the jars to lose water. be sure there is at least 2-3 inches of water before adding the jars to the canner. I also found if my canner was not level it contributed to water loss. I was using a 20 year old canner at the time of my mistakes. It was not very forgiving. I have a newer canner that is not nearly as fussy. hope this helps!

Sep 21, 2012
losing liquid
by: ty

oOoh!! Maybe THAT'S what's wrong. been losing liquid in my corn bad this year!! even worse when i just did CREAM corn. I'll try mason lids next time n see if it makes a difference.

Sep 30, 2012
losing liquid
by: Sheryl

What I would like to know about losing liquid (especially when canning chicken or any other meat) is this: when the meat juice seeps out does this corrupt the seal between jar and lid? Is the meat in the jar still safe to eat or is it compromised because of the broth getting into the seal?

Thank you

Sheryl, as long as the seal remains intact your food is still sealed and safe. (assuming you used proper processing methods)

Oct 02, 2012
Canning Lids hyper-suctioning
by: Anonymous


We have been preserving and canning all late summer and fall. we leave about 1/2 in head space, with no problems or seeping of liquids, but recently we've been having a few of the lids almost "hyper-suction". They are dented in more than the others and are also creasing extra.

What's this from and is it a problem or how would I know if it was a problem?

I've not heard of this before. I'd say just watch the seals, as long as they stay sealed your food is still protected from spoilage. (assuming you used proper methods)


Jan 07, 2013
canning mustards and collards
by: jjl

Is time canner. I canned collards and mustards together. What would be the shelf life?

Standard recommendation is one year. However there is no magical one day it is good the next day bad so if you have them more than a year... just pull them to the front of your cupboard and plan on using them soon.

Of course that is assuming you pressure canned them the appropriate amount of time and pressure.

Aug 30, 2013
canning green beans
by: Anonymous

My pressure cooker was losing steam while processing green beans. I lowered the heat and cook the jars of bean the allotted time. Will the green beans still be ok to eat?

No they must be processed at the correct amount of pressure the entire time.

Jul 19, 2014
Canning Beans
by: Tom

Have been trying to can string beans. First batch just fine but batch two lost most of the water from the jars and batch 3 all of the water.
I have to conclude that the pressure is higher in the jars than inside the canner. The lids are the same in all instances (Ball lids) as was the processing temps and times.

The canner is an older Mirro from around 1981 and the gasket seems to be pliable but there is a sort of strange "safety seal" that has a metal cork that runs up against a rubber seal. Could it be that the rubber seal has deteriorated and is passing pressure?

I run the canner on Medium heat. By the way the instructions on canners explicitly say to run cold water over the canner to release the pressure. If you don't get the canned items out fairly soon you will wind up with a WAY mushy overcooked product.

Tom, I'm not sure what instructions manual you are looking at but you don't want to run water over the canner to cool it. You want to let it cool naturally with no help. This is what is causing your liquid loss in the jars. The canner pressure is cooling faster than the pressure in the jars, which causes the liquid to be pushed out.

The only time I've seen recommended to cool with running water is with a pressure Cooker when you are preparing a meal. Are you possibly working with a cooker not a canner? When canning never cool the canner artificially.

Jul 30, 2014
bent seals
by: Deb

I know what I done wrong I just don't now how to fix it I put too manY green beans in the jars when I took them out of the pressure cooker the seals were bent how do I fix it Thanks

Sharon's reply:

If you catch it right away you can either re-process the beans in the jars that did not seal. Or you can just freeze those beans. Reprocessing might give you mushy beans so I'd also suggest freezing them.

Aug 09, 2014
losing liquids
by: Bobbi

It was good to read about this but I guess that we need to get a new Ball canning book? Our book says 15 lbs of pressure for 3 minutes for the pints, remove from burner and cool down with cold water to avoid overcooking?

Sharon's reply:

This must be for pressure cooking, not canning. # minutes is right if you are just cooking the beans for the dinner table.

Aug 09, 2014
Mirro pressure canner-loss of liquid in jars
by: Rose

Hi, new pressure canner here... just seen a post about an older Mirro Pressure canner... Mine is a 1977 12 Qt! In the manual the front part is for use a pressure cooker and does recommend running the canner under cool water to ensure release. The back part of the manual clearly states in caps never under any circumstances run the pressure canner under water- Jars need to cool naturally and slowly! It also says it takes about 45 min ( have tested this and found it pretty accurate) for the canner to fully release pressure and then will be safe to open. The manual also says to let jars rest about 5 min before removing them. The only variable I can see in loosing water is cold pack vs. hot pack.

Aug 13, 2014
Pressure canning green beans
by: Lisa

I am new to pressure canning and green beans was my first attempt.
The instruction manual said pressure cook for 3 minutes at 15 psi which i did and the results were great. However after re-reading the instruction manual i realized they were instructions for "cooking" green beans and not canning to preserve. Several days have elapsed, would it be safe to open the jars, put new lids on them and pressure can them for the 30 minutes recommended? The liquid in the jar is slightly cloudy as well. Anything to worry about?
Thank You!

Sharon's comment:
Unfortunately Lisa, since a few days have gone by and I'm assuming the jars were not refrigerated I would not eat the beans. Just look at it as a learning experience and toss the beans. I hate wasting food! But it is not worth getting sick over.

Also be sure you have a canner that will hold at least 4 quart jars. This is the smallest size that is safe for home canning. The smaller pots are just for pressure cooking, not canning.

Aug 26, 2014
Butter beans losing water.
by: anneAnonymous

I have put up 28 Qt jars of Butter beans, processed as directed. They sealed fine. The jars are only half full of water. Are they ok to add to my stash? will they still taste good? How long will they store? Help! I am new to canning butter beans and they are so expensive!

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