Tips to avoid botulism

Janice Fields

I received a call last week about home-canned green beans that were improperly processed, which sparked a memory of botulism poisoning from home-canned green beans back in 2008 for an Ohio grandfather and his three grandchildren.

A Virginia couple died in 2007 from improperly canned vegetables. More recently, botulism poisonings from other home-canned vegetables have been reported. This led me to read more on the topic at, a website with the goal to increase food safety awareness and safe practices in the food service industry.

My food safety hero, Ben Chapman with North Carolina State University, is a writer for the blog.

Botulism poisonings in the United States are rare, but there still not something I recommend increasing your risk to. Botulism toxin causes paralysis, starting at your eyes and mouth and working down the body, which often leads to not being able to breathe without a ventilator.

Eating a microscopic amount put one Ashe County woman in the hospital for 11 weeks on a ventilator. It took more than a week to determine the problem and start treatment.

Got your attention? She didn’t even swallow the improperly home-canned carrots that poisoned her. She thought they tasted funny and spit them out.

The funny taste was most likely from spoilage organisms, not from the toxin. Bacteria and toxins that cause food borne illness cannot be seen, smelled or tasted. Scary, huh?

A recent botulism outbreak occurred in Ohio after a church potluck. Consuming potato salad made from home-canned potatoes led to 20 illnesses, as well as the death of a 54-year-old woman. My heart goes out to the person who canned those potatoes.

Most of us food preservers enjoy sharing our homemade products with family and friends, but we must follow safe procedures.

Low-acid foods — including all vegetables except rhubarb — should be processed for a specific amount of time in a pressure canner. The temperature in a pressure canner can reach 240 degrees, which is hot enough to destroy botulism spores.

There is not a safe canning recipe for summer squash or zucchini — it is best to freeze or pickle these items. It is also recommended to only freeze spaghetti squash.

High-acid foods, such as fruits — excluding figs, tomatoes and melons — and pickles should be processed for a specific amount of time in a boiling water canner. Botulism spores cannot grow in high-acid foods, but using a boiling-water bath will destroy yeast, molds and most bacteria.

All is not lost: You can safely preserve fruits and vegetables. The key is to use a tested recipe from a reliable source with the correct equipment and follow a few food safety precautions. Old family recipes, though precious, may not be safe.

Reliable sources of recipes and guidelines for preserving foods that I often use include “Ball Blue Book Guide to Preserving,” the National Center for Home Food Preservation and the “USDA Complete Guide to Home Canning” — which is available online as a free download.

A list of reliable sources can be found at