There are many reasons for the loss of liquid during processing. Loss of liquid may cause food to darken, but does not interfere with the keeping qualities unless the liquid loss has caused food, grease or seeds to lodge under the lid and prevent a seal.
Some reasons for loss of liquid during processing could be:
- Jar packed to full or too tightly.
- Starch foods absorb some liquid.
- Air bubbles were not removed at the time of packing.
- Jars in a boiling water bath canner were not covered with 1-2 inches of water.
- Pressure canner was allowed to fluctuate during processing.
- Letting a canner stand too long after pressure returns to zero.
- Removing the jars too quickly from the pressure canner after removing the cover.
Can a pressure canner or water bath canner be used on a ceramic cook top?
For water bath canners or pressure canners to work successfully on a ceramic cook top, the canner bottom must be ﬂat, in contact with the cook top and extend no more than 2 inches beyond the design on the cook top surface.
Most heavy cast aluminum pressure canners work on smooth top stoves. The lighter weight stamped aluminum canners usually have a concave bottom. If the concavity is greater than 1/8th inch the canner will not perform well.