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Canning With a Pressure Canner

Source: University of Wisconsin

Review the directions for using a pressure canner each time you use it. If the instruction book is gone, write the manufacturer for a new one. When you write, give the model number and any information you can find on the canner. If you do not have this information, describe it and give the approximate age.

Before the canning season, put water in the canner and bring it up to pressure in the usual way to make sure it works properly. When canning, use enough water in the canner to heat and cool jars at a steady rate and to ensure against boiling dry. Water two or three inches deep (not less than 1 quart) is usually enough, although you may need more for a long processing period in a canner with a weighted pressure control gauge. The weight allows a little steam to escape regularly throughout processing.

Heat the loaded canner quickly. When you start heating, leave the petcock open, or pressure regulator off until steam flows steadily--about 10 minutes after the first steam appears. This lets the canner expel air and ensures the pressure it reaches is true steam pressure. Be sure to vent the canner this way, no matter what the instruction book says. Failure to vent the canner can result in inadequately processed foods.

When a dial gauge registers the desired number of pounds or when a weight control signals the canner has reached pressure, adjust heat to keep the needle steady, or the pressure control rocking gently to release steam at a low but steady rate. Time accurately! If the pressure drops below the desired process pressure at any time during processing, bring pressure back up and start timing again for the full time needed.

When processing time is up, turn off the heat and remove the canner from the heat. If the canner stays on a hot unit, it will cool more slowly. Cool until pressure is zero, and then wait about two more minutes. Open petcock, or remove weight slowly to prevent a sudden change of pressure that might cause jars to lose liquid. Never try to hurry the cooling of any pressure canner by pouring cold water over it, or by wrapping wet cloths around it. As soon as steam stops flowing freely from the vent, loosen the cover and remove jars. Open the canner away from you a few minutes after the pressure reaches zero to prevent the canner lid from sealing very tightly.

If you have further questions, please contact your county office of the NDSU Extension Service.

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