Canning 101

Canning can be a little intimidating if you’ve never done it before. Newer cookbooks sometimes stress food safety in such a strident way that even the most comfortable cook can get a little nervous at the prospect of doing something wrong. Don’t get me wrong – food safety is reeeeallllly important – but sometimes the tone of these rules can scare off interested people. So – canning wannabes – never fear! Your local food adventurers will guide you on your way to preserving your harvest!

In home canning, heat is applied to jars of food interrupting the natural decaying process and killing the microorganisms that cause food to spoil. The process also forces the air out of the jars, forming a vacuum seal that prevents any air or microorganisms from entering the jar, and allows the jars of food to be stored at room temperature for an indefinite period of time. It’s also important to sterilize your jars before you can anything so there aren’t any micro-critters in there to begin with! You can can high acid foods such as fruit, pickles, chutney, jam, salsa and tomatoes with added acid (lemon juice) in a standard hot water bath. This is not a safe method for low acid foods such as vegetables and meats, which need to be canned in a pressure canner since there’s no extra acid, sugar or salt to help preserve the food. When canning, always follow a recipe and use the jar size dictated in your recipe as this relates to the necessary processing time.

Necessary Tools: canner (or large, deep pot) with a rack that can fit inside the pot so your jars don’t sit directly on the heat, Mason jars and two-piece metal lids, tongs, a rubber spatula, a ladle and a wide-mouth funnel.

Home Canning Steps

Wash and prepare your produce according to your recipe.

– Wash jars with hot, soapy water and rinse well. Place jars in the canner (or large, deep pot) with enough water to cover them. Bring to a boil. Boil for 10 minutes, sterilizing the jars. Leave the jars in the canner until you are ready to fill them.

– Place the snap lids in a small bowl or pot and pour very hot water over them. Allow them to sit a few minutes in the water to soften until you are ready to use them.

– Prepare your recipe. Fill your jars (with the help of the funnel and ladle) with your recipe. Follow your recipe regarding how much “headspace” to leave. The general rule is: ¼ inch for 125mL and 250mL jars and ½ inch for 500mL and 1L jars.

– Remove any air bubbles in the jar by running the rubber spatula along the inside wall of each jar. Wipe the rim of the jar to remove any food spills. Place the snap lid and metal screw band on the jar, tightening gently. This is often called ‘fingertip tight’. Repeat for each jar.

 – Now you are ready to “process” the jars in the hot water bath. Place the filled jars into the canner of boiling water. Begin timing, following your recipe regarding necessary processing time. Ensure that the water covers the jars by a min. of 1”.

– When your processing time is up, remove the lid and remove the jars from the canner without tilting. Place them on a heat-protected surface in a draft-free area. Do not tighten the screw bands or move the jars for a number of hours. You will likely hear a popping sound when the seal forms. You can test the seals by checking that the centre of the snap lid curves downward. Store your jars in a cool, dark place.

This is pretty standard canning procedure and will result in safely preserved food. For more advanced tips, check out our post called Canning 201.

Here are some of our favourite resources and those recommended to us by others:

Foods of Spry’s Field: Cooking and Preserving Then and Now by the Urban Farm Museum Society
Busy Person’s Guide to Preserving Food by Janet Chadwick
Wild Fermentation: The Flavor, Nutrition, and Craft of Live-Culture Foods by Sandor Ellix Katz
Putting Food By – by Janet Greene
Preserving Food Without Freezing or Canning by the Gardener and Farmers of Terre Vivante
Preserved by Nick Sandler
The Complete Book of Pickling by Jennifer Mackenzie
National Center for Home Food Preservation website

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