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Home canning and water-bath basics


Mason Jars filled with Strawberry Jam

For a wide variety of reasons, home canning is becoming popular again. In fact, in a recent article about home canning, the New York Times reports that the “sales of equipment already up almost 50 percent over last year, according to the Jarden company, which makes both Ball and Kerr canning supplies.” Some people are canning for the joy of the flavor that you cannot buy from industrial food giants. Others consider it a political act, similar to buying local, seasonal and organic food from a farmers market. Still others are preserving food because it is economical, especially if they grow their own produce or buy in bulk during the growing season. Plus, canning is a way of preserving food for years without the worry of last winter’s power outages where one can loose a whole freezer full of food.

Last week I wrote about making strawberry jam and someone had a question about the basics of water-bath canning. Canning was out of favor for quite a while, probably because of our busy lifestyle, and it is quite natural that we have forgotten the how-to’s of canning. Fortunately there are plenty of books, websites, and even community gatherings that are willing to share their wisdom (and sometimes their food).

Here are the basics of water-canning, or boiling water processing, which I have learned from past experience and the Ball Blue Book of preserving.

Equipment Needed:

Boiling-Water Canner with wire rack
Mason Jars – reusable for generations – make sure they are not chipped or cracked
Canning lids and rings (the rings can be re-used, the lids must be new)
Jar Lifter* – remove hot jars safely with these sure-grip tongs
Canning Funnel* – A plastic jar funnel fits in jars for easy filling
* These are not necessary, but save a lot of time and frustration

While you are working on your recipe (follow it exactly to make sure that you have enough sugar or acid to complete the canning process), you can be sterilizing your jars, lids and rings. Put the empty, clean jars into the wire rack and boil the jars for 10 minutes. This also makes the glass jars warm enough to avoid cracking when you put in your hot recipe (such as strawberry jam). In a small kettle, boil the rings & lids for 10 minutes as well.

Fill your jars with the finished recipe to the correct amount of remaining space or headspace: ¼” headspace for jams & pickles and ½” headspace for high-acid foods such as fruits and tomatoes. Stir food inside jar to remove air bubbles. Clean the rims of the jar with a clean, damp cloth to ensure correct sealing. Place lid on jar and then tighten the ring just to the point where you feel resistance.

The boiling-water canner should be about half full with water and set on a simmer (180 degrees F). Using the jar lifter, place jar onto canner rack in the canner. Carefully lower the rack into simmering water. The water level must cover jars by 1 to 2 inches (add water if necessary).

Put the canner lid in place, and bring water to a rolling boil. Make sure that the water maintains this boil for the whole processing time (check your recipe for the correct amount of time). After the time period is finished, turn off heat and remove canner lid. Let canner cool 5 minutes before removing jars.

Remove jars from the canner, setting jars upright on a dry towel or cutting board to cool. Leave 1 to 2 inches of space between jars. Do not tighten bands if they became loose during processing. Let jars cool naturally 12 to 24 hours before checking for a seal. During this time you will hear the sweet popping sounds of your canning lids as they “pop” down into sealed position. To test the seal, press down on the lid to determine if it is concave and that it does not flex up and down. Also, remove the ring to check that you cannot lift the lid with your fingertips. If these are all true you have achieved a correct seal. If not, you will want to consider other storage methods for the food you just processed – refrigerate or freeze it so that it is not wasted. Happy Canning!

Canning Workshop:  If you are in the Knoxville area, there is a canning workshop located at the Anderson County High School Vocational Kitchens on June 9th and June 11th from 4 to 6 pm – click here for more information. The cost for both days is $30 and you get to learn canning techniques as well as keep the produce that you can that day.


  • rachelle 5 years ago

    mmmmm good...can't wait to try this wonderful jam!!! : )

  • allyson 5 years ago

    Thanks for all the info! I have to try to start canning! Keep the articles coming! I love them!