Sterilizing Your Jars

I've heard of sterilizing your jars in the microwave or the dishwasher, but I'm not comfortable with the safety of that.  I prefer the following method:

  • Put about 2 inches of water in a pan that will hold several jars.  In areas with hard water, add a few drops of vinegar to prevent calcium buildup on the jars.
  • I have two canners and I use one for sterilizing. You can also use a roasting pan with the rack in place. In the bottom, put either a jar rack or a towel, to keep the mouths of the jars from hitting the bottom of the pan.  Place on burner and turn on heat.
  • Wash your jars using dish soap and hot water.  Rinse.  Inspect each jar for nicks or cracks.  Even a little nick along the top can keep a jar from sealing properly.
  • Place jars, opening down, on the rack/towel.  Cover pan with lid and leave jars until they are too hot to touch.  I would say they should be in there for at least 10 minutes.  Watch your water levels and add hot water as necessary.
  • Add your lid flats, as they will need to be sterilized, too.
  • Remove jars carefully using a jar lifter and clean towel.  Place them right-side-up in your tray or on a towel in preparation for filling.

I'm not paranoid about sterilizing.  If your jars are clean, you make the effort to sterilize them, and you follow the correct procedures for pressure or water bath canning, your product should be safe.  I've been canning most of my life (nearly 50 years!).  I learned from my mom, who learned from her mom...


Water Bath

You need:

  • A large kettle with a lid and a cooking rack that fits in the bottom.  The kettle needs to be at least three inches taller than your jars.  If you don't have a cooking rack, you can put a towel or wash cloth in the bottom and the jars will hold it down.  You don't want your jars resting directly on the bottom of the kettle.
  • Jars for your recipe, either quart, pint, or half-pint.
  • New lids, composed of flats and rings.  (I do reuse my rings, as long as they are clean and rust-free, but always buy new flats.)
  • Jar lifter
  • Handy Canning Tool that is graded on the end to mark jar fill levels, and can also be used to stir out air bubbles from you product.

Add water to your kettle sufficient to cover jars by two inches.  Again, add a tablespoon or so of vinegar if you live in an area with hard water, to prevent calcium buildup on jars.  Remember that the jars themselves will take up space and increase the water level.

Turn on heat under kettle, so water can be heating while you sterilize and fill your jars.

When jars and lids are sterile and your product is ready to put in the jars, carefully fill your jars to the appropriate level for your recipe, using jar gauge to measure head-space and remove any trapped air bubbles from the product.

Wipe the rim of the jars with a clean cloth.  Any product left on the rim will prevent proper sealing.

Apply the lid flats and screw on the lid rings.  Tighten just using your hands, as tight as you can go reasonably.

Using jar lifter, place jars in kettle.  Jars should just fit in, not bumping into each other.  If there is room for a lot of movement, insert towels between the jars to fill up the space.  Clinking together may crack a jar, and there is nothing worse than the sound of a jar breaking while in the canner.  All that work gone to waste!

Water should be two inches above the top of the jars.  Add hot water if needed to increase level.  DO NOT ADD COLD WATER!  You will crack your jars.

Cover and bring to a boil.  Start your timer when a full boil is reached.

After time is up, turn off stove.  Carefully remove jars using jar lifter.  Place jars on a towel, out of a drafty area, leaving some space between jars for air movement.  

Wait to hear the lovely sound of the jars sealing!

After 12 hours, check lids for seals.  The center of the lid flat should not flex up and down if it sealed correctly.  At that time, carefully remove the rings and gently wash the outside of the jars to remove any product that leaked out during processing.  Do not damage the seal!  Label jars with date and contents, and store in a cool, dark place.

***If after 12 hours you have any jars that have not sealed, you will need to refrigerate that product and use it right away.  You may reprocess that product by heating it and using a new jar and lid, but using it now is often easier.  I always mark jars that have failed with a piece of duct tape.  That way if it fails again, I know there is something wrong with the jar and I dispose of it or re-purpose it for non-canning use.***