A. Yes. If it is deep enough it may be used as a water-bath canner ([p. 4]). Or you may use a pressure canner to process fruits and tomatoes at 0 to 1 pound pressure without having the containers of food completely covered with water. Put water in the canner to the shoulders of the jars; fasten cover. When live steam pours steadily from the open vent, start counting time. Leave vent open and process for the same times given for the boiling-water bath.
Q. Must glass jars and lids be sterilized by boiling before canning?
A. No, not when boiling-water bath or pressure-canner method is used. The containers as well as the food are sterilized during processing. But be sure jars and lids are clean.
Q. Why is liquid sometimes lost from glass jars during processing?
A. Loss of liquid may be due to packing jars too full, fluctuating pressure in a pressure canner, or lowering pressure too suddenly.
Q. Should liquid lost during processing be replaced?
A. No, never open a jar and refill with liquid—this would let in bacteria and you would need to process again. Loss of liquid does not cause food to spoil, though the food above the liquid may darken.
Q. Is it safe to use canned food if liquid is cloudy?
A. Cloudy liquid may be a sign of spoilage. But it may be caused by the minerals in hard water, or by starch from overripe vegetables. If liquid is cloudy, boil the food. Do not taste or use any food that foams during heating or has an off odor.
Q. Why does canned fruit sometimes float in jars?