How to Double Stack Jars in a Pressure Cooker

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Things You'll Need

  • Large pressure cooker

  • 2 canning racks (one comes with the canner)

  • Pint canning jars

  • Lids and screw bands

  • Jar lifter

Low-acid foods like meat, poultry and most vegetables must be canned with a pressure cooker to eliminate the risk of botulism. While clostridium botulinum bacteria live on the surface of most fresh foods, they only grow into botulism in the absence of air. The extreme heat inside a pressure cooker (temperatures of 240 to 250 degrees Fahrenheit) destroys these bacteria and allows you to safely eat the hermetically sealed food inside. The downside is that it is a slow procedure. Speed it up by double stacking the jars; some large pressure cookers hold 18 pint jars in two layers.


Step 1

Place one canning rack in the bottom of the pressure cooker and pour 2 to 3 inches of hot water over it.

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Step 2

Place filled pint jars on the rack and rest the second canning rack on top of them.


Step 3

Place the second row of pint jars in the canner and securely fasten the lid.

Step 4

Depending on the type of canner you have, either open the petcock or remove the weight from the vent port. Set your stove's burner to high and heat the canner until steam flows from the vent port or the petcock. Pressure cookers can't reach maximum temperature when air is trapped inside, so venting is a critical step to ensure that food is not under-processed.


Step 5

Vent steam for 10 minutes, then close the petcock or place the weight back on the vent. The canner will now pressurize in three to five minutes.

Step 6

Begin timing the processing when the petcock starts to rock or jiggle or the reading on the pressure gauge indicates that the desired pressure has been reached.


Step 7

When the processing is complete, turn off the heat, remove the canner from the heat and the burner and let it rest until the pressure gauge goes back to zero or no steam escapes when the weight is nudged.

Step 8

Open the petcock or remove the weight, open the lid and remove the jars with a jar lifter. Avoid setting the jars in a breezy or cold area since this could lead to breakage.


Step 9

After 24 hours test the seals on each jar. There should be no movement when the top is pressed with a thumb. Any unsealed jars can be reprocessed or refrigerated and the contents eaten within a few days.


Should the pressure drop below the recommended level while you are processing, increase the heat and restart the timing, using the original recommended process time.

Always operate your pressure canner according to the manufacturer's instructions.

Only use canners that have an Underwriter's Laboratory (UL) approval. Allow the canner to cool on its own; don’t force it by running it under cold water or releasing the pressure. This can result in unsealed jars and loss of liquid.


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