Canning Safety Tips

By Pat Banker, Master Food Preservation Instructor, Cornell Cooperative Extension

It's harvest time. Tomatoes, corn, beets, carrots, peppers and other fruits and vegetables are readily available from farmers' markets, roadside stands, and your own gardens. Preserving the bounty safely for the winter can be economical, delicious, and safe if laboratory tested rules for food preservation are followed. Since 1994, testing facilities, universities and the USDA tested recipes and directions used in food preservation books seven times in different areas of the country and under different conditions to assure that directions to be used would assure the product canned would be shelf stable, nutritious, flavorful, and free from both food spoiling bacterium and deadly bacterium such as clostridium botulinum-botulism. It was found that many canning instructional materials were not safe.

Fruits including tomatoes, can be safely canned in boiling water bath canners with a lid if their pH level is lower than 4.6. The lower the pH level, the higher the acid level content. The addition of lemon juice to fruits being processed to raise the pH level will both insure the acid level is safe and can help preserve the color of your canned high acid products. Salsa and other pickled products can safely be processed in boiling water bath canners due to the addition of high acid vinegars. Vinegar for canning and pickling must have 5% acid content. The acid content can be found on the product label.

Low acid foods including all vegetables, tomato based products mixed with vegetables or meat, and all meats must be canned in a pressure canner. There is no safe amount of processing time for these items if a boiling water bath canner is used. Low acid foods must be processed in a pressure canner following processing times required for the altitude at which the items are to be canned. Either a dial gauge or rocker gauge home canner may be used. Dial gauge canners need to have the gauge tested on an annual basis as being off by as little as 1lb pressure reading on the gauge can lead to an unsafe canned product. Testing may be done locally by visiting the Cornell Cooperative Extension office in Malone or if you bring the gauge to the Paul Smiths VIC Homesteading Festival on September 30th free of charge. Gauges may also be mailed to the manufacturer to be tested with no charge.

Home canned foods are a wonderful addition to any home pantry. Safety in processing is necessary and relatively easy to follow. If you have food preservation questions, contact the Cornell Cooperative Extension office, 518-483-7403 or visit the website: http://franklin.cce.cornell.edu/. Watch the website for future canning and food preservation classes.