Extension Connection: Unsafe canning methods create spoilage

This week we&8217;ll discuss unsafe canning methods.

The open-kettle method is an outdated method considered unsafe.

In this method, foods were heated in a kettle then poured into jars with a lid placed on the jar. No processing was done. Using this method often caused spoilage because bacteria, yeast and molds were not killed by further processing. The growth of these microorganisms, in addition to spoiling the food, often cause lids to unseal. This results in a real danger of botulism.

Steam Canning is a newer method that is not considered safe.

The jars are heated by steam. However, safe processing times have not been developed, and steam canners are NOT recommended for either high- or low-acid foods. Low-acid foods canned in these canners are potentially deadly because of possible botulism contamination.

Other Unsafe Methods: Canning food in the microwave oven, electric ovens, slow cookers or crock pots can be extremely dangerous, especially with low-acid foods, and is not recommended. So-called canning powders are useless as preservatives and do not replace the need for proper heat processing.

Guard against spoliage. Don&8217;t taste or use food that shows any kind of spoilage. A bulging lid or leaking jar is a sign of spoilage. When you open the jar, look for other signs, such as spurting liquid and off-odors or mold.

Improperly canned low-acid foods can contain the botulinum toxin without showing signs of spoilage. Low-acid foods are considered improperly canned and not safe if the food was not processed in a pressure canner, if the gauge of the canner was inaccurate, if USDA tested processing times and pressures were not used for the size of the jar, style of pack and kind of food being processed, if the proportions of ingredients were changed from the original approved recipe or if the processing time and pressure were not correct for the altitude at which the food was canned.

For more information on food preservation, contact Angela Treadaway your Regional Extension Agent at 205-410-3696.