currently in Austin


Basics for Home Canning

Mason Jars

Home canning is an easy way to preserve and share the bounty of your home garden or farmer’s market finds. Sales of canning products increased 30 percent in 2009 with the renewed interest in backyard gardening. I will discuss boiling water canning in this program.

Molds, bacteria and fungi are all around us and on every food surface. Many of them are beneficial while others can be harmful. During the canning process the food will be exposed to sufficient heat to destroy harmful microorganisms that may cause food spoilage. Do not use a jar of canned goods if they appear cloudy, foamy or have an ‘off’ color or odor. Canned goods may be stored up to a year in the cupboard.

Follow recipes carefully to ensure good results. Do not adjust sugar, vinegar or salt amounts in recipes as this can lead to food spoilage. Use 5 percent acidity white vinegar unless otherwise specified. For best results, use a canning salt that is processed without caking agents or iodine as these can affect color and crispness of the finished products.

Certain foods like okra, carrots, green beans and asparagus are considered ‘low acid foods’ and must be canned in a steam pressure canner at 240 degrees to avoid botulism contamination unless sufficient vinegar is added to the recipe (as in pickling) to avoid contamination. Pickled foods can be processed in the water bath canner at 212 degrees.

Equipment you will need:
Boiling water canner or a large enough stock pot to cover the jars with at least one inch of water. The canners you buy come with a jar rack to raise the jars off the bottom of the pan to allow water to thoroughly circulate under the jars. You may use a cake rack in a deep stock pot to get the same results. You will need a lid to tightly cover the container.

Canning jars in half pint, pint or one quart sizes. These jars are made with special threads to seal properly with home canning screw bands and lids. The jars should have no nicks or chips in the necks which would inhibit a proper seal. Jars may be reused many times if they are in good condition.

Jar lids and screw bands come in standard or wide mouth types. Screw bands may be reused if they are not worn or rusted but the lids should not be reused.

Tools to make the job easier:

  • jar lifter
  • lid rack
  • magnetic lid wand
  • canning funnel
  • nonmetallic spatula
  • timer to ensure proper processing time

Steps for Canning

  1. Wash jars, lids and bands in hot, soapy water and rinse well.
  2. Keep jars warm until ready to use to prevent breakage when filling with hot food. You can keep them in the dishwasher or heat them in simmering water.
  3. Fill the canner half full with enough water to cover jars with at least one inch of water.
  4. Fill jars with prepared food and allow the required head space from the rim to allow for food expansion. The Ball spatula has measurements for calculation of head space.
  5. Remove any air bubble from the jar with a non metallic spatula. These can increase the airspace and impact canning effectiveness.
  6. Wipe any food from the rim and center a new lid on the jar. Twist the band on fingertip tight. Ensure bands are not overly tight – air inside the jars must be able to escape during canning.
  7. Place filled jars into canning rack and lower into simmering water. Jars should be covered with at least one inch of water. Cover with the lid and heat to a steady boil. Boil jars for the time specified in the recipe.
  8. Turn off heat and let jars stand in water for 5 minutes. Remove the jars from the water and place on a towel covered counter-top or a cooling rack for at least 12 hours. (Do not re-tighten bands after processing as this might interfere with the sealing process.)
  9. Press on the center of the cooled lid. If the jar is sealed the lid will not flex up or down. If the jar did not seal it may be refrigerated and used immediately.
  10. Jars may be stored for up to one year. Bands should be removed to wipe the jars to make sure there is no water caught under the bands which may cause them to rust. Bands may be left off for storage.
  11. Label your jars with the item and the date after they are cool.


For more information on canning consult the Ball website: