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Common Canning Questions


It is definitely canning season! My phone is ringing regularly with many kinds of questions. I thought I would share with you some of the more often asked questions the past few weeks.

Steam Canners are on sale, are they safe to use?

Steam canners are not safe to use and we do not recommend using them. They consist of three of three pieces: a shallow pan filled with about two quarts of water, a perforated rack on which the jars stand and a large dome cover. The promoters of steam canners say the benefits include: less time to pre-heat the water, less water used, cannot boil over, and saves energy.

The major concerns with the steam canners include:

  • Cold spots where temperatures are below the 212 F that is needed for heat penetration. This leads to underprocessing and poses a potential risk of food spoilage.
  • Steam will be released as it builds up under the dome and then cools the canner down.
  • Increased jar breakage may occur since jars are not separated by a rack in the canner.
  • Steam burns may occur when removing the lid. The dome lid must be lifted straight up and steam will pour out around your hands and arms.

After processing my fruits or vegetables I notice that some of the liquid is loss? Is that safe? What caused it?


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.


Can my pressure canner or water bath canner be used on a solid element cooktop?

Solid element cooktops require heavy gauge, flat, smooth bottom utensils that have no more than 1-2 inch overhang beyond the element.  Most pressure canners are too large to be used on solid element cooktops.

Most water bath canners are either too light in weight (aluminum) or have ridged bottoms (enamel) and thus are not suitable for the use on solid elements.

What can be done to make soft jellies firmer?

For jellied products using powdered pectin: Mix in a saucepan ¼ cup sugar; ½ cup water; 2 tablespoons bottled lemon juice, and 4 teaspoons powdered pectin. Bring to a boil while stirring. Add 1 quart jam or jelly and bring to a rolling boil over high heat, stirring constantly.  Boil hard for ½ minute.  Remove from heat, remove foam and fill sterile jars, leaving ¼-inch headspace. Adjust new lids and process in boiling water bath canner for 10 minutes.

Can I preserve peach, pears, apricots or other fruits without sugar?

Yes, but sugar does add flavor, helps fruit maintain its firmness and color. Sugar moves into the fruit tissues and keeps it firmer.  Extra-thin or thin syrups do help add the sweetness and helps prevent the fruit from floating.

If you still don’t want to use sugar or cannot use sugar in canning fruits, then consider using water or fruit juice (diluted or straight) for the liquid. Canning with artificial sweeteners can be tricky.  Some of them loose their sweetening abilities or turn bitter.

For more information about preserving foods contact Sandy Brown at WSU Extension at 397-6060 ext 7712.