Home Food Preservation

Canners and canning methods that should not be used by consumers

Steam Canners The steam canner was designed as a means to process foods using steam without the aid of pressure. The manufacturer claims this process uses less water, saves time and energy, and recommneds identical processing times as those required for boiling-water bath treatments.

Studies have concluded that:

1. Atmospheric steam canners result in significantly lower product temperatures at the beginning and end of the scheduled process when compared to water-bath canning.
2. Use of steam canners as instructed by the manufacturer would result in under processing and considerable economic spoilage.

Micro-Dome Food Preserver - Micro-Dome Food Preserver Recalled Washington, DC--The U.S. Consumer Product Safety Commission (CPSC) in cooperation with Micro-Dome of San Ramon, CA, has warned consumers of certain safety hazards associated with the use of the "Micro-Dome Food Preserver" manufactured by Micro-Dome and sold and distributed to consumers after August 1987. The CPSC has also urged consumers to destroy all food that has been preserved using a Micro-Dome Food Preserver....[MORE]

Solar Canning The heat generated from captured sunlight is not a reliable method to process acid foods and should never be used to can low-acid foods. Picture of solar canner

Oven Canning Oven-canning is extremely hazardous. The oven canning method involves placing jars in an oven and heating. In oven canning, product temperatures never exceed the boiling point because the jars are not covered. It is, therefore, not safe to use for low-acid products (e.g. meats, most vegetables) which require temperatures higher than 212 F.

Because this process fails to destroy the spores of Clostridium botulinum, it can cause the food to become toxic during storage. Also, canning jars are not designed for intense dry heat and may explode resulting in serious cuts or burns.

Open Kettle Canning The open-kettle method involves placing hot food in jars and sealing with no further heat treatment. This method is NOT recommended for home canning because the amount of heat applied may not be sufficient to destroy bacteria and the product may spoil quickly or cause llness when consumed.

Microwave Processing Microwave oven cannot be used for home canning. Microwaved food reaches 212 F but heating is not uniform. There is also a danger of explosion of the jars within the microwave oven or as food is being removed from the oven.

Dishwashing Processing Processing canned foods in a dishwater cycle is dangerous. The temperature of the water during the cleaning and rinsing cycle is far below that required to kill harmful microoganisms. Thus the product will be underprocessed and unsafe to eat.