Area gardens have been growing well, and all kinds of produce are becoming ripe. It’s time to get out the canners and preserve some of those vegetables and fruits for yummy eating next winter.
Produce (and meat) that are not canned using current research-based canning methods can pose serious health risks. That means using the right canner for each type of produce.
Pressure canning is the only safe method for home canning vegetables. Vegetables are low-acid foods and must be canned in a pressure canner at the appropriate pressure to guarantee their safety.
Deadly food borne illness can occur when low-acid vegetables are not properly preserved. Clostridium botulinum is the bacterium that causes botulism food poisoning in low-acid foods, such as vegetables.
The bacteria produces spores in vegetables and meat that can only be destroyed by temperatures that reach 240 degrees Fahrenheit (F) for the correct amount of time in a pressure canner.
The Clostridium botulinum bacterium is harmless until it finds itself in a moist, low-acid, oxygen-free environment or a partial vacuum. These are the conditions found inside a jar of canned vegetables.
Under these conditions, the bacterium can grow and produce toxins dangerous to people and animals. DO NOT process low-acid vegetables using the boiling water bath because botulinum spores can survive that method.
Acid foods, like fruits, can be canned in a boiling water bath. The botulinum bacteria is harmless in an acid environment.
It is recommended that all acid goods, including fruits, jams and jellies and concentrated tomato products all receive a boiling water bath treatment to kill possible molds and other bacteria from the air. Open kettle canning is not recommended.
Several varieties of low-acid tomatoes have been developed. These create a concern when canning
USDA recommends that tomatoes be acidified, and only then can they be canned using a boiling water bath.
To acidify tomatoes, add 1 tablespoon lemon juice or ¼ teaspoon citric acid for each pint of tomatoes. Add 2 tablespoons bottled lemon juice or ½ teaspoon citric acid for quarts.
It is best to use standard canning jars that are free from defects. Use tow-piece metal lids prepared according to the manufacturer’s directions on each individual box.
For best preserving results, select only fresh, young, tender produce that is not over ripe. If at all possible, can within 3 hours of harvesting.
If canning takes place later, store produce in the refrigerator to keep it fresh. Rinse all produce thoroughly in cool water. Do not soak to prevent loss of flavor and nutrients.
Salt and sugar are optional in home canned vegetables and fruits. Sugar does help preserve color, texture and flavor.
The local foods trend is encouraging many folks to grow a garden and preserve their own food. That is great, but safe, research-based preservation methods must be used.
Use these websites to check USDA and Ohio State University Extension recommended preservation methods: http://ohioline.osu.edu/ and http://nchfp.uga.edu/
Free programs on “Home Canning and Freezing” will be offered by OSU Extension, Delaware County on Tuesday, July 29th at the Delaware Main Library, in Delaware; Thursday, August 7th at the Delaware County District Library, Orange Branch; and Tuesday, August 19th at the Sunbury Community Library in Sunbury. All of these FREE classes will be from 6:30 pm – 8:30 pm. Free pressure canner testing will be available before and after the sessions for dial gauge canners. (Only the lid is needed.)
So, gear up and get your families involved in preserving produce this summer. Happy eating this winter!
Barbara A. Brahm is an OSU Extension Educator, Family & Consumer Sciences