Sunday, August 7, 2011

Pressure Canning -- Don't Blow Your Top

Many people have told me they don't pressure can because they've heard stories about canners blowing up and making a mess of kitchens. Maybe this will help allay their fears.

First, if appropriate, heat up what you're canning. In this case, we're canning pizza sauce, so we need to make it hot.
In the meantime, check the petcock/counterweight hole on the canner's lid. Can you see daylight through it?
If you can, great. If not, you need to clear the way. Sterilize your jars. I rinse clean jars with water and microwave them for 3 minutes, or pour boiling water over them. Fill them with pizza sauce or whatever you're canning, leaving the proper headroom, 1/2 inch from the top for this pizza sauce. Place a sterilized canning lid on top of each jar and screw the ring tight. Place the jars inside the canner with enough water to rise two inches up the side of the canner.
"Only four jars?" says Virginia.

I hate to use a 7-quart canner for only 4 jars, but in this case that's all I have to can.

Check the gasket for the canner's lid, making sure it's properly lined up, then turn the lid on tight. This is hard to do with our canner. I do the best I can. The less tight, the more likely it will leak and drip water onto your stovetop, which is no big deal so long as it doesn't drip too much and you have enough water inside.
Now for a step some folks forget. Don't put the counterweight on yet. Turn on the stove burner and wait for steam to come out the hole on which you will set the counterweight. After the steam begins escaping, wait at least 10 minutes to be sure the air is expelled from inside the canner. Air trapped in the canner lowers the temperature for a given pressure and may result in under-processing. This step is very reassuring. You see the steam coming out the right place, so it's hard to picture an explosion in the wrong place. After 10 minutes, set the counterweight on. (Some of your pressure cookers have pressure gauges; I haven't used them, so I can't help you there.)
Use the 10 pound hole for this pizza sauce.
Wait for the counterweight to begin to jiggle as it lifts up to let out pressure and down until the pressure builds up again. Listen until the jiggle goes at a good clip (the directions for your canner should provide better advice on what to listen for), then set a timer for the appropriate time, 40 minutes for this pizza sauce.
As time passes, if the jiggle sounds too aggressive, turn the heat down, but not so low the jiggling stops.

When the time's up, turn off the burner, remove the canner from the burner and let it cool. Don't try to take off the pet cock until the pressure has relieved or you may get burned. Ditto, opening the canner. Probably the best thing to do is something else so you forget about it for a while. After it's cool, open her up and remove the jars. Presto!

By the way, you can remove the rings now. If the lids have properly sealed, the rings are no longer necessary and there's no need to keep a huge supply of rings around. And -- if I've messed up -- let me know, please.

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