10 November 2012

Food preservation: General canning tips

Now, I can't give you specific instructions on how to can food using every available pressure canner. The instructions should have come with the canner, after all.

I can tell you that I generally wash my jars in the dishwasher beforehand, and keep them in the dishwasher to stay warm until I'm ready to fill them. (You can also heat them up in a pan of water on the stove.) Hot food + cold jars = broken glass. Remember this.

Use a funnel to fill your jars, and carefully wipe the rim of the jar before you put the lid on if you think you may have dripped any liquid or grease on it. (I use a paper towel dipped in vinegar for this). Crud on the rims will spoil the seals.

On the same note, be generous with the headspace. That's the fancy word for the empty space above the food and below the lip of the jar. Hot food expands, and pressure canners make food REALLY hot. Too little headspace and this hot food will expand until it squeezes out of the jar. Which then leaves crud on the rims. Which spoils the seal. Sensing a pattern here?

A glub of vinegar in the bathwater will keep nasty hard water deposits from forming on the outside of your jars. It doesn't really hurt anything, it's just ugly.

Do you know that little jar lid tightener thingy that seems to come with every set of canning tools? Yeah, I don't use it. Hand tight is good enough. If the lid on the jar is too tight when the contents get hot and expand, the jar explodes. Not as scary as it sounds, it amounts to a jar I have to replace and a mess to clean up inside the canner. Don't cut yourself.

Don't rush after your processing time is done. Let the pressure canner depressurize slowly as per the directions. Trust me, after the pressurized-hell-on-stovetop that has taken place to sterilize the contents of those jars you want no part of them until they've had a chance to cool down a little.

I've got a pantry shelf I keep empty, as a place to stick my hot jars. If I leave the door cracked open the heat can still escape but the jars aren't in a draft. Hot jars + cold air = broken glass.

Don't fiddle with the jars after you process them! Leave them alone until they're no longer warm to the touch. After the jars are cold you can fiddle with them to your hearts content. You can then take the band off (and should, or they rust) and tug on the lid to make sure the seal holds.