Enjoy the fruits of your labour through canning
By Fiona Wagner • Bankrate.com

Put simply, fresh food is cleaned and prepared, jars are sterilized and filled, then the capped jars are heated to seal the lid and destroy any potentially dangerous microorganisms such as bacteria, yeast and mould.

There are only two ways to safely heat process food: boiling-water bath processing and pressure canning.

Stovetop boiling-water bath canners, available at most hardware stores, are large-lidded kettles with a metal rack that holds canning jars. High acid foods, such as fruits (including jams and jellies) and pickled products (including relishes and chutneys) can be safely processed in a boiling-water bath.

Low acid foods, such as vegetables, meats, seafood and poultry, must be processed in a pressure canner, which is the only way to safely destroy heat resistant microorganisms.

(Tomatoes are somewhat of an exception: with a pH of 4.6, they fall right in the middle of the low/high acid spectrum. If you prepare tomatoes on their own, you can use a kettle, but once you start mixing in vegetables or meats, you'll need a pressure canner.)

Pressure canners are more expensive, starting at about $200, but without one, you risk spoilage and even serious illness or death.

"Botulism is the main problem with consuming home canned foods that have not been properly preserved," says Marnie Webb, communications officer for the Food Safety Network at the University of Guelph. "It's a very serious problem caused by Clostridium botulinum bacteria. A jar can be in good condition and you wouldn't know it's contaminated. Canning (of low acid food) has to be done properly, otherwise you have no idea."

While there are lots of different tools to help make canning easier, most tools such as measuring cups and stock pots will be already in your kitchen. That said, no matter what your grandma says, you can't just use any glass jar.

Mason jars, specially made to withstand the rigours of home canning, range in size from half a pint to one quart and can be used over and over again as long as there are no nicks or cracks. They can be purchased new at hardware or department stores or found used at yard sales or through online classifieds such as Craigslist, Kijiji or even Freecycle, where I found four dozen perfectly good one-quart jars.