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"Why are my jars of canned pears exploding?"

It's a mystery! I've recently been canning pears by packing them fresh in hot jars and then pouring hot syrup over them. However, when I processed the jars in a hot water bath, some of the jars exploded and I lost the fruit. Others never sealed. I've used the same procedure with apricots and this never happens. Please do some sleuthing for me!

A frustrated canner,


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Dear Laura,

The next time you are preserving pears, simmer them gently in syrup for five minutes before putting them in the canning jars. This is called a "hot pack" method, and is useful for pears because, like apples, they contain an abundant amount of air.

Cooking them lightly before packing them in jars allows their tissues to soften slightly first so the air can more easily escape. Then during processing, there's not so much pressure exerted when air bubbles are released into the limited space of a canning jar. This doesn't happen with apricots because, like many other fruits, they contain less air than pears and apples.

Here are a couple of other considerations too: We're not sure what type of bottles you're using but "jars breaking" during processing raises the point that it's best to use jars designed by preserving companies. They are made of thicker glass than many other types of commercial jars, and they can withstand the high temperatures of a boiling-water bath, so they're less likely to break during processing.

Also make sure you allow some space between the fruit/syrup and the jar lid by NOT packing the fruit right up to the top. This space is called "head space" and it allows room for the fruit to expand during processing. Usually this is 1/2 inch (1 cm), but note that the recommended head space differs for various foods. You can find this out (and lots of other hints too) by purchasing an up-to-date preserving book, usually available in the preserving section of local supermarkets or check the Web sites of companies that make canning supplies such as Bernardin's (

Good luck and thanks for writing.
Anne & Sue


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