I keep seeing questions and FB comments about the
word "siphoning" and I'm not sure that is the word that I would use.
They describe siphoning as; a jar that has a much larger headspace that
originally canned or the liquid appears in the water of the canner with residue
on the lid, ring, and/or jar.
To better explain this phenomenon you have to
realize what is happening in the canner. The process inside the canner is
heating the recipe to the internal temperature of the canner (waterbath 212
degrees; pressure canner 240-250 degrees) and as a result the food will boil
and expand. Air will escape around the two piece lid. The process does two
things; 1) kills any microorganism that are in the jars contents 2) remove
oxygen and help form a high vacuum in the jars. Good vacuums form tight seals
which keep liquid in and air and microorganisms out. 1
The video below is my recent batch of beans just
taken out of the canner demonstrating the contents are still boiling when they
are removed from the canner.
Troubleshooting the result of "loss of
liquid" or "excessive headspace" can be done during the process
of filling the jars. Here are a few things to be mindful of;
1) If you didn't measure the correct headspace
the food will "boil over" in the canner. It will escape out the top
of the jar and the end product will be short in the jar of either liquid or
product.
2) If you did not remove the air bubbles before putting on the
lid the results from the boiling canner will create action in the jar. The food
will take up the air space not previously removed making your jars look like a
boil over when in fact it didn't have enough liquid to start with.
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There are many that fear that the "boil
over" or the "excessive headspace" will be reason to put those
jars in the refrigerator and that they are not shelf stable. The key is how
the jars sealed.
From the picture to the right as the jars cool the
change in temperature causes the lid to pull down sealing the jar.
If you have excessive headspace and the jar doesn't
seal the processing time may not have been sufficient to drive out the air.
This jar must also find a home in the frig. But if the jars seal in either of
these conditions they are shelf stable.
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Tomatoes I pressure canned
in November 2010
still shelf stable!
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The last and most important procedure, to ensure
that you will have an indication of a bad jar in the future, is to store all
the jars without the rings on them. I know for many that is contradictory to
what you know but there is a good reason to do so. I will use the examples from
the jar to the left as my prime candidate.
Without a ring, the jar with excessive headspace,
though it has properly sealed, may start to have growth of bacteria. The
bacteria will cause; 1)pressure under the lid causing the lid to slide
off or 2) the center of the lid will bulge or 3)when removing the
lid to use the contents of the jar the lid will have no resistance to your
fingers pulling it off. If you leave the ring on and if bacteria forms
the ring will stop the lid from moving. Though the lid may not bulge, given
time, it could reseal itself trapping the microorganism that may lead to e.coli
and botulism.
Filling and doing the steps to process a perfect
jar requires practice. You will continue to have some that don't come out quite
right here and there, but don't give up. Some foods can be tricky because of
their natural expansion such as dried beans and lentils.
Good canning recipes specify the headspace, but a
general rule is use 1 inch for low acid foods (such as vegetables), 1/2 inch
for fruits and pickling, and 1/4 inch for jams and jellies.
Additional reasons during the
Pressure Canning process:
Here are some of the troubleshooting tips that I
can give you about the loss of liquid in your jars while pressure canning:
1. Make sure that if you are doing
beans or other foods that will absorb liquid that you account for expansion.
You will want to fill your jars 1/2 to 3/4 of the way full with your recipe and
complete up to the headspace with your hot liquid. The recipe will tell you how
to fill. If not ask me!
2. Make sure to be good about the
headspace. 1" means the space between the top of the jar to the start
of the level of the food!
3. When putting on the rings make sure they are
only finger tight. Cranking the rings on may cause undue pressure on the
lids making it harder to release the air from the jar.
4. Make sure to start simmering
the water in the bottom of the canner before loading the jars. This will help
once the lid is on bring up the temperature in the canner.
5. Once the lid is
on the canner, make sure to vent the canner for the full 10 minutes. The
canner internal temperature is important in creating enough steam and heat and
will also help in the liquid not boiling over.
6. Be diligent during processing to
keep a "fairly" steady temperature under the canner to not
process for long periods of time at excessive amount of pressure. That will
cause overboiling in the jars for the additional pressure over time.
7. When you are done with processing
make sure that you do not move the canner because shifting the canner
may cause the liquid which is now up to the lid to spill out. Let the canner
cool naturally. Do not force the issue by knocking or pushing the weight
off of the vent to release the steam faster.
8. Don't let the jars sit in the
canner beyond the time it takes the canner to cook. The internal
temperature will take a while to cool which will allow your recipe to continue
to cook and possible boil over. Take your lid off once the pressure gauge
returns to zero or your lid lock goes down.
9. Once you have removed the lid
let the jars sit in the canner for 10 minutes. This will allow the jar
additional time to depressurize. I have seen jars siphon after the lid is off
when taking them out right away so wait the 10 minutes before taking them out.
I
know that it's a lot of things to remember but practice makes great jars and
the loss of liquid can be avoided in most cases!
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