> THE BASICS

Preserving is on a sustained upswing with a new generation of home cooks. It’s not as hard as it seems but does require some equipment and know-how. This is a guide to the water-bath method, which uses the heat of boiling water to seal the jars after a vacuum removes the bacteria-causing oxygen. Only high-acid food such as fruits and pickles are safe using this method, which uses heat to expand the jar’s contents and create an oxygen-free environment to prevent bacterial growth. A pressure canner, which kills the bacteria that causes the potentially fatal disease botulism, is usually required for low-acid food. Check the government of Canada’s home canning safety website; the food preservation company Bernardin’s website, or the U.S.-based National Center for Home Food Preservation. Christine Manning leads us through the steps

Step one

Some people prefer to cover lids with hot water to help soften the glue and form a seal with the glass jar. Glass jars can be reused, but buy new lids. Jars should be clean and dry but don’t need to be sterilized if processing for more than 10 minutes using a water bath or pressure canner, according to the National Center for Home Food Preservation.

Step two

Cook jam according to the recipe. Don’t be surprised by the amount of sugar; it’s necessary for the process and traditional jams have a set sugar content. Jam sets around 220 F at low elevations. Or, try the spoon test: stir a metal spoon through bubbling jam. If jam drips off quickly, it’s still too runny. Slow, “lazy” drips are the best and jam should coat the back of the spoon.

Step three

Skim any foam. After jam is set but still warm, ladle jam into jars or use a funnel. Ensure the proper “headspace” between the jam and the lip of the jar. A quarter-inch will do for jam. A measuring tool is often included in canning starter kits. Any jars that aren’t full can be stored in the fridge like any jam, but should not be canned. Wipe the lid rim clean of any jam as it can prevent proper sealing.

Step four

Shake excess water off lids and place on the jar. No need to press down. Screw on the metal ring band until you first feel resistance, not too tight. Boil a large canning kettle or wide pot. Use a trivet or rack to prevent jars from sitting on the bottom of the pot and lower jars into boiling water using jar lifter. Boil vigorously for 10 minutes or according to recipe with at least one inch of water covering the jars.

Step five

Remove using jar lifter. Place on a tea towel, not directly on a cold counter as the hot glass may crack. The divot in the lid will be pulled down once jars are vacuum sealed with a telltale popping sound. It can take hours for jars to fully seal. (If the lids still make the popping sound when you push on it, the jar is not sealed.) Store in a cool, dry place without the metal ring bands.

Some advice

Tips from Mississauga’s Yvonne Tremblay, a past “grand champion” of the jams and jellies competition of the Royal Agricultural Winter Fair:

The best-quality fruits make the best-tasting jams.

Don’t mess around with recipes, which have been tested to get the right balance of acids and sugars; stir well to completely dissolve.

If the fruit burns while simmering, don’t scrape the bottom of the pot; empty the fruit into a clean pot and continue cooking.

If using commercial pectin as a setting agent, check the expiry date before starting.