Prepared by Pamela Schmutz, HGIC Food Safety Specialist, and Angela Fraser, Extension Food Safety Specialist, Clemson University. (New 4/11.)
A boiling water bath canner is simply a big pot with a removable rack to hold the jars, and a fitted lid. It must be big enough to cover the jars with 1 to 2 inches of boiling water.
Boiling Water Bath Canner
If you have an electric stove, be sure that the canner has a flat bottom, and that the canner is no more than 4 inches wider in diameter than the element or burner that you will be using. When the canner is centered on the element, the canner should not extend more than 2 inches on any side. This is important so that all the jars will be processed uniformly.
Use a pressure canner not a pressure cooker. A pressure canner must be able to hold at least 4 quart-size jars. Most 16-quart or larger canners are big enough. All pressure canners have a removable rack, an automatic vent/cover lock, a vent port (steam vent), and a safety fuse. Only use canners that show the Underwriters Laboratories approval of safety symbol(UL).
A pressure cooker or pressure saucepan is smaller and is not intended for processing foods in jars. A pressure cooker will heat up and cool down faster than a pressure canner, and the canned foods may not be processed long enough to destroy the microorganisms. Differences in the sizes of the pressure cookers and in the thickness of the food being processed make it impossible to adjust the times safely.
Dial-gauge canners have a dial that shows the pressure. These canners must be watched during processing to be sure the pressure does not fall below the required level and they must be tested every year to make sure the dial is registering correctly. A dial-gauge canner is a good choice for those that live at higher altitudes because precise pressure adjustments are easy to make.
Weighted-gauge canners have weights for 5, 10 or 15 pounds pressure that are placed over the vent and rock or jiggle when the correct pressure is reached. Follow the manufacturer’s instructions on how often the gauge should rock or jiggle. The sound of the weight rocking or jiggling indicates that the correct pressure is being maintained, so these canners do not need to be watched during processing. Weighted gauges do not have to be checked each year. A disadvantage for those living at higher altitudes is that precise pressure adjustments cannot be made as you are limited to 5, 10 or 15 pound weights.
Whether your pressure canner is brand new, a family heirloom or a yard sale find, be sure all parts are in good condition.
Do a test run on your canner if it is new, or at the beginning of the season.
Contact your local Extension office or the Home & Garden Information Center (1-888-656-9988) for information on how to have your dial-gauge canner tested.
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