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Old canning jars might be unsafe for preserving food


Many of us found it difficult to purchase canning supplies last year during the pandemic. With everyone staying at home and the uncertainty of the food supply, having a garden, and preserving your own food seemed the way to go. Boiling water bath canners and pressure canners sold old out everywhere and you could not find a jar or box of lids. With this shortage of supplies at retail stores and online, people began purchasing jars at flea markets and antique malls. And while there is not necessarily a food safety risk in using canning jars purchased at these locations, there is a risk of breakage because of the age of the jars. Canning jars do not have a manufacture date stamped or embossed into the jar. They may have a date or even a large number (0-15) on the bottom of the jar, but that date is the patent date, and the large number is the mold date. Unfortunately, neither of those reflect the year the jar was made.

The National Center for Home Food Preservation says, “Very old jars can weaken with age and repeated use; they break under pressure and heat.” Jars should always be examined carefully for cracks, nips, and chips in the body and around the sealing edge before use. It also helps to know the history of the jars and how and where they were stored. Extreme changes in temperature can weaken the glass, which cannot be seen upon visual examination.

Antique canning jars should only be used for decoration or dry food storage, not food preservation. In addition, vintage jars with wire bales and rubber rings should not be used for canning. Purchasing new jars is a better investment over time than buying used jars at a flea market or yard sale. If you take good care of your jars, always use a rack in the bottom of the canner, protect them from extreme temperatures, and avoid chipping or cracking, you can use them for many years.

Reference: National Center for Home Food Preservation,

For more information on food safety and other topics contact the Meade County Extension office at 270-422-4958 or email me at

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