A heavy-duty pressure canner with a locking lid and either a dial or weighted gauge (or both) shouldn’t be confused with a pressure cooker or pressure saucepan.
It’s possible to find pressure canners at places like Three Bears Alaska, Alaska Butcher Equipment & Supply, Alaska Mill Feed & Garden Center, Trustworthy Hardware, Wal-Mart and online.
If you want to buy a used canner from a garage sale, Craigslist or Alaskaslist, carefully look it over and make sure the canner isn’t bent or warped, that its metal-to-metal or rubber gasket maintains a good seal and that replacement parts are available. If it has a dial gauge, take it to a local Cooperative Extension office, where a staffer can ensure the gauge is functioning properly.
Having the following equipment helps make canning more efficient and safe:
• Magnetic lid lifters make it possible to safely remove lids from hot water.
• Use jar lifters (with rubber coating on the jar end) to safely remove hot jars from the canner after processing.
• A measuring tool ensures the proper amount of headspace inside the top of the jar.
• Bubble freers remove air pockets inside jars that could affect how evenly the food heats during the canning process. They are usually plastic or rubber and do not damage jars as metal implements tend to do.
• Canning funnels prevent spills as food pours into jars.
When canning, use current recipes and follow modern canning guidelines, especially regarding canning times and the amount of pressure to use.
Safely canning pint-size jars of salmon, for example, requires 100 minutes of processing, using 10 pounds of pressure with a weighted gauge, 11 pounds of pressure with a dial gauge and even more pressure if canning is taking place in a high-altitude area. Quart jars require 160 minutes of processing time.
The canning process:
• Wash jars and lids in hot, soapy water and rinse well. The flat lids should be placed in a pot of hot but not boiling water, to soften the sealing compound. Follow the manufacturer’s instructions regarding water temperature, which can range between 160-180 degrees Fahrenheit.
• Fill the jars. Use a measuring tool to ensure the proper headspace, wipe clean the rim of the jar, then tighten—but don’t overtighten—the lid.
“What happens in the jar is that the product gets hot, pushes air out,” Shallcross said. “Overtightening prevents the air from escaping and bends the edge of the flat (lid) so it doesn’t seal.”
• Place the jars in the canner—on a rack—with 2-1/2 to 3 inches of tepid water inside the bottom of the canner.
• Canners have different types of lids but all will close securely so the top will not “blow” off and can’t be removed until the pressure is all the way down. Line up the arrow or mark on the canner lid, keeping the lid even. Pull up the opposing sides, gently and evenly tighten the screws keeping the lid down.
• Turn heat to “high” and let the air exit the canner. Steam should begin flowing out of the canner.
• Let the steam flow out in a strong plume for 10 minutes. Time it. This step ensures there is even heat throughout the inside of the canner.
• When the 10 minutes are up, use a gloved hand or potholder to close the vent or petcock and bring up the pressure to 10 pounds with a weighted gauge or 11 pounds with a dial gauge. This should occur quickly, 5 to 15 minutes.
• The vent cover or weighted gauge will begin rocking, jiggling and releasing steam periodically when it is up to the correct pressure.
• Write down the time and calculate when 100 (or 160) minutes will elapse. Begin timing the canning process.
• Don’t leave throughout the process. Stay nearby to be sure the canner maintains the correct pressure throughout the process. If the pressure drops below 10 or 11 pounds, you must bring the canner back up to pressure and begin your processing time over again, from the beginning
• When the time is up, turn off the heat and let the canner cool on its own. The cool-down time will vary, but may take as long as 45 minutes. When it’s cool, use gloved hands to release the valve.
• Open the pressure canner, using the lid to deflect the steam safely away from your face.
• Use a jar lifter to place jars on an insulated out-of-the-way surface— a towel spread out on a counter, for example. Placing a hot jar on a cool surface will likely shatter the jar.
• Let the jars cool for 12 to 24 hours. DO NOT TOUCH THEM. The flat and ring lids will be loose. The ring lids’ function is merely to keep the more critical flat lids attached. Flat lids have a soft sealing compound on them that will solidify and seal once all the air has moved out of the jars. Disturbing that lid while it’s loose will compromise that seal, making it necessary to process the jars all over again, from the beginning.
• Label the jars. Write the date, what is in the jar, how it was processed—10 pounds for 100 minutes, for example.
• Store the jars in a cool, dark place. Don’t stack the jars, because that could disturb the seal of the flat lid.