Easy to grow in a home garden and delicious year-round, green beans are a popular home-canned food. Just like any other home-canned food, it is important to always use research based procedures and recommendations. For example, green beans should always be preserved by pressure canning.
People still canning green beans at home using the boiling water canner instead of tested pressure canner process are risking food loss and even worse, possible death or serious poisoning. Green beans canned this way look fine coming out of the canner, but often turn cloudy and jars pop open, even sometimes with force. These beans are definitely spoiling from being under processed. But it could be worse: even if the jars still look good, it is possible that they contain botulism toxin from this unsafe canning practice.
Jars of improperly canned green beans or other vegetables and meats can contain the deadly botulism toxin without showing signs of spoilage.
Spores of Clostridium botulinum bacteria, as found naturally in soils, are very, very heat resistant. Even hours in the boiling water canner will not kill them if they are inside your jars of beans. Left alive after canning, they will eventually germinate into actively growing bacterial cells that will produce a deadly human toxin when consumed. This bacteria likes the conditions inside closed jars of low-acid foods (such as vegetables and meats) sitting at room temperature, so they must be killed during the canning process for safe storage.
The spores of clostridium botulinum can be destroyed only by canning food at a temperature of 240 degrees or above for a specific period of time. Since this temperature is above the boiling point of water, it can only be reached in a pressure canner. Therefore vegetables, (except tomatoes), meat and seafood must be canned in a pressure canner for safety reasons.
Below is the correct method for Canning Green Beans (from University of Georgia, So Easy to Preserve):
Hot Pack – Cover green beans with boiling water; boil 5 minutes. Pack hot beans into jars, leaving 1-inch headspace. Add ½ teaspoon salt to pints; 1 teaspoon to quarts, if desired. Fill jar to 1 inch from top with boiling hot cooking liquid. Remove air bubbles. Wipe jar rims. Adjust lids and process as directed below.
Raw Pack – Pack green beans tightly into jars, leaving 1-inch headspace. Add ½ teaspoon salt to pints; 1 teaspoon to quarts, if desired. Fill jars to 1 inch from top with boiling water. Remove air bubbles. Wipe jar rims. Adjust lids and process.
Process with a Dial Gauge Pressure Canner at 11 pounds OR in a Weighted Gauge Pressure Canner at 10 pounds pressure: Process Pints for 20 minutes and Quarts for 25 minutes.
Please be safe when canning foods for you and your family. Knowledge and recommendations change over time with scientific developments. Use up-to-date recommendations and canning books, and not just rely on recipes from past generations. A helpful website with research based recipes and food preservation information is the National Center for Home Food Preservation (www.uga.edu/nchfp)
For questions locally, you may also Linda Hyder with UT Extension – Sevier County at 865-453-3695 or [email protected]. Enjoy canning with the confidence you are doing it correctly for the health of your family.
The University of Tennessee Extension offers its programs to all eligible persons regardless of race, color, national origin, sex, age or disability and is an Equal Opportunity Employer.