Green Beans MUST be Canned with a Pressure Canner

Adair Hoover, Program Assistant,
Home & Garden Information Center

Fresh green beans are available in South Carolina between the months of May and October. Canning them is an excellent way to have this local resource available throughout the year.

There are many advantages to preserving foods at home but be aware that outbreaks of foodborne botulism involving two or more people occur most years and are usually caused by home-canned foods. Safely canning green beans requires using a tested and reliable method. The following explains why pressure canning is required for green beans, why using recipes and methods that have been passed down from previous generations are not safe and where to get reliable information.

Pressure Canning Green Beans

Since the late 1920s most of the outbreaks of food-borne botulism in the United States have been caused by improperly home-canned foods. Green beans and a variety of other vegetables and meats are low acid foods (the pH of these foods is above 4.6) so they MUST be pressure canned. If you don’t use a pressure canner for low acid foods (including green beans), you risk creating an ideal environment for the growth of the bacterium Clostridium botulinum. Though the bacterial cells are killed at boiling temperatures, they can form spores that can survive these temperatures. The spores grow well in low-acid foods that are stored in the absence of air. When the spores begin to grow, they produce the deadly botulinum toxin (a nerve poison) that causes botulism. The only way to ensure that these spores are destroyed is to process foods at a temperature of 240° F (28oF above boiling at sea level). This temperature cannot be achieved with a water bath canner and that is why it is not an acceptable method for canning green beans. A pressure canner is the only type of home canning equipment that can achieve a processing temperature of 240° F. As altitude increases, water boils at lower temperatures. For pressure canning, the pressure is increased. The directions for canning foods are usually for an altitude of 0 to 1000 feet. If you are canning at an altitude over 1000 feet, check for altitude adjustments for each type of food. You can contact the Clemson University Home & Garden Information Center to determine your altitude or check with your local airport.

Extensive research has been done in the area of pressure canning. Exact processing times, temperatures and pressures are vital to safe and successful canning. For more information on pressure canning see HGIC 3020, Home Canning Equipment; HGIC 3030, Canning Foods-The pH Factor; and HGIC 3025, Choose the Right Canner for Home Canning.

Using Old Recipes & Methods

A very common mistake made in canning is using recipes and methods that have been passed down from previous generations. It may be tempting to follow methods and recipes if they’ve been used for years with no known problems but it only takes one bad batch to make you or your family become very ill or to possibly die. Keep in mind that many of these recipes were created using outdated canning techniques or have lost accuracy over the years due to misprints and other communication errors.

Where to Get Reliable Information

There are numerous safe recipes available for preserving foods that may be relied upon for up-to-date, safe and accurate information. For a list of sources that provide current research-based information, procedures and instructions see HGIC 3001, Finding Reliable Recipes for Safe Food Preservation.

Strictly following pressure canning instructions, using well maintained equipment and choosing reliable recipes will help ensure that you are producing a safe and tasty product to be enjoyed throughout the year.

Canned Green Bean Recipe

For great canned green beans try the following up-to-date recipe from Elizabeth L. Andress and Judy A. Harrison, So Easy to Preserve, 5th ed.

Canned Green Beans (Snap, Wax or Italian)

Select tender, crisp pods. Remove and discard diseased and rusty pods. Wash beans and trim ends. Break or cut into 1-inch pieces or leave whole.

Hot Pack – Cover beans with boiling water; boil 5 minutes. Pack hot beans into hot 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 hot cooking liquid. Remove air bubbles. Wipe jar rims. Adjust lids and process as directed below.

Raw Pack – Pack beans tightly into hot 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 water. Remove air bubbles. Wipe jar rims. Adjust lids and process.

Process in a dial gauge pressure canner at 11 pounds pressure OR in a weighted gauge pressure canner at 10 pounds pressure. Process pints for 20 minutes and quarts for 25 minutes.

We encourage you to review HGIC 3240, Canning Beans, Corn & Peas and/or attend a Clemson Extension Canning workshop, before you pressure can your green beans for the first time. See the PSA on-line store for workshops. 

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This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed.