In a pickle? Chef Colleen answers questions about pickling and canning.

I’ve received so many questions from readers about pickling and canning that I thought I’d share them with all of you too.

Q: Colleen, are pickling and canning the same thing?

A: They are both methods of making fresh produce last longer, but they are not the same thing. Pickling uses salt, sugar, or acid to help foods last longer – up to two weeks or so in the fridge. Canning on the other hand uses heat to destroy bacteria that can cause spoilage and illness.. Home canned foods, as long as they are not opened and processed correctly, will last for months or years without refrigeration. Once opened, the canned foods (also called preserves) should be refrigerated and will last for several months.

Q: Can I sterilize the jars I want to use for pickling or canning in the dishwasher?

A: Yes you can. Many modern dishwashers even have a sterilization setting on them for this purpose. You don’t need to sterilize the jars used for pickling but running them through the dishwasher is a great way to make sure you’re using clean equipment.

You can also sterilize your canning equipment in the oven. Just place your clean jars and lids on a baking sheet and bake at 180C (350F) for 15 minutes.

In all cases, let your sterilized equipment air dry. Don’t use a towel since that can cause bacterial contamination and/or leave lint in your jars.

Q: How full should I fill the jars?

A: You don’t want to leave too much empty space at the top of your canning jars. A gap between the top of the jar and the lid of 1 to 1.5 centimetres (about 1/2 inch) is perfect.

Q: I heard a scary story if filled canning jars touch each other while being boiled for sterilization, they can explode. Is that true?

A: That is not true. Canning jars should not explode. However, as you boil the jars in the canning pot, they could rattle around and break each other. That’s why people who do a lot of canning have a canning rack to hold all the filled jars steady and separate as they boil.

Q: How long do I boil the jars of preserves for?

A: You should boil the jars for 15 minutes. You only need the water to be at a simmer or gentle boil and the water should completely cover the jars by at least 2.5 cm (1 inch)

Q: How do I know if the preserves have been heated enough and the contents have been sterilized?

A: Your preserves need to reach an internal temperature of 82C (180F). When you’re done boiling your jars, open one up and use a thermometer to check the internal temperature of the contents. If you have reached 82C or higher, your preserves are done. Reseal the jar you have opened and put it back in the canning pot of hot water and let it cool until the lid forms a seal again.


 If the internal temperature of the jar is not yet at 82C, reseal the jar and boil it and the rest of the jars for another 15 minutes and test again.

Q: How do I know my jars are sealed?

A: When your canning jars are properly sealed, the lid will look concave. That is, it will dip inward at the centre. When a jar is opened, breaking the seal, you’ll hear the pop of the seal being broken and the jar lid will become flat or even slightly convex.

Q: If a dishwasher is hot enough to sterilize jars, is it hot enough to actually do the boiling-sterilizing step of the filled jars?

A: Great question and the answer is – I don’t know. I am going to do an experiment and find out though. Watch this page for updates!