Michigan Fresh: Basic of Water Bath Canning (HNI117)

There are two methods of packing food into canning jars – raw pack and hot pack.

Basics of Water Bath Canning

''Use a water bath canner for processing acid foods – fruits, tomatoes, pickled products, jams, jellies and preserves.  A water bath canner is a large, deep kettle that has a cover and a rack to hold jars.  You can also use a big, covered stockpot that is deep enough to allow water to be 1 to 2 inches over the tops of the jars with room for a rolling boil.  A rack for holding jars can be purchased wherever canning supplies are sold.

There are two methods of packing food into canning jars, raw pack and hot pack:

  • Raw pack:  pack raw, thoroughly washed prepared (peeled, cut-up, pitted, etc.) food into clean, hot jars.  Raw fruits and vegetables should be packed tightly because they will shrink during processing. 
  • Hot pack:   heat prepared food to boiling, simmering 2 to 5 minutes and promptly pack food loosely into clean, hot jars, according to recipe directions.    

Cover raw- or hot -packed food with boiling water, cooking liquid, syrup or juice.  Using a plastic spatula, bubble freer or wooden spoon, go around the inside of the jars to remove air bubbles. Leave the amount of headspace at the top of the jar according to directions in recipe. 

As soon as the food is packed into jars, wipe the jar rims with a clean damp cloth or paper towel.  Put on the lid with the sealing compound next to the jar rim.  Screw the band down , fingertip tight so that it is on securely.   Do not tighten too tight,—there has to be enough ‘give” for air to escape from the jars during processing.  Process foods promptly after packing into jars and adjusting lids. 

Steps for successful –water bath canning:

  1. Fill canner half full with water; then cover and heat.   
  2. Using a jar lifter, place jars filled with food on the rack in the canner.  If necessary, add boiling water to bring water to 1 to 2 inches over tops of jars.  Do not pour boiling water directly on jars.
  3. Place cover on canner.
  4. When water comes to a rolling boil, start counting the processing time.  Keep water at a gentle and steady boil for the entire processing time. 
  5. If necessary, add more boiling water to keep water 1 to 2 inches above jars.
  6. As soon as the processing time is up, turn off the heat under the canner and use a jar lifter to remove jars from the canner using a jar lifter. If liquid boiled out of the jars during processing, do not open them to add more.  Do not retighten screw bands.
  7. Place hot jars upright on a rack or towel to cool.  Leave space between jars for air to circulate, keep them out of direct breeze—this can cause jars to break.
  8. Leave jars on counter to cool 12 to 24 hours.  After jars are cooled completely ( 12 to 24 hours), check to be sure all lids have sealed.  If the jars are not sealed, the food  must be reprocessed in clean jars with new lids, or the unsealed jars must be refrigerated and the food eaten within two to three days.
  9. Remove screw bands and check lids for secure seal.  Wash, dry, label and store jars in a cool, dry place. 

Safety tips

For best results use only standard canning jars with the manufacturer’s name on the side.  These jars are tempered to withstand temperature extremes, and the seal edge is smooth and flat so lids will seal properly.  Check all jars, new or used, for cracks, chips or nicks.  Such defects can result in breakage or sealing failure.  Lids should only be used once; you may reuse screw bands that are in good condition.  Do not use screw bands that are bent or rusty. Store canner in dry place to prevent rust.


More information

Prepared by: Joyce McGarry, Extension educator

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