Canning is a great way to preserve your garden bounty and share it with family and friends, but it must be done correctly so it’s not dangerous. If you plan to can your harvest, it’s important to be knowledgeable about proper techniques so you can make sure your home-canned vegetables aren’t contaminated by the germ that causes botulism. Home-canned vegetables are the most common cause of foodborne botulism outbreaks in the United States.
What is botulism?
Botulism is a rare but serious illness caused by bacteria that produce powerful toxins that can lead to serious illness, paralysis, and even death. The bacteria produce hardy spores that can survive in soil. Fruits, meats, fish, and vegetables could be contaminated with the bacterial spores before they are canned. In oxygen-free environments, like those in vacuum-sealed jars used for canning when the canning process is not carried out correctly, the spores produce one of the most lethal toxins known. It can be deadly to take even a small taste of food that has been contaminated with these toxins.
What are the symptoms of botulism?
Symptoms may include double or blurred vision, drooping eyelids, slurred speech, difficulty breathing or swallowing, dry mouth, and muscle weakness with paralysis. Symptoms can start anywhere from 8 to 36 hours after eating contaminated food.
When should someone seek treatment?
Call 911 or get to an emergency room as soon as possible if you see signs of this disease. Immediate treatment drastically reduces the risk of death and long-term health problems.
Are there ways to tell if a jar of food might be contaminated?
It may be difficult to tell from the container if the food inside is contaminated with the botulism toxin, but there may be some clues. If the container is leaking, bulging, or swollen, or it looks damaged or cracked or abnormal in any way, don’t eat what’s in it. If it squirts liquid or foam when you open it, throw it away, and then wipe up the spill using a quarter cup bleach for each 2 cups of water. The toxin can be absorbed through the skin, so always wear waterproof gloves to protect yourself when opening suspicious containers. Finally, if the food is a funny color, or is moldy, or smells bad, don’t eat it. When in doubt, throw it out!
What’s the best way to be sure you haven’t contaminated your canned foods?
Use a well-tested recipe and closely follow instructions. Use modern preservation techniques such as those recommended in the USDA’s Complete Guide to Home Canning and the right equipment for the kinds of foods you are canning. You should use a pressure canner or pressure cooker and be sure the gauge on it is working properly. Pay special attention to the processing times for low-acid vegetables such as green beans, carrots, and corn.
- Home canning and botulism from the CDC
- National Center for Home Food Preservation information on canning
- USDA Canning Recommendations
(Note: A Closer Look at Your Health airs at around 6:50 a.m. most Tuesdays. This is an edited transcript of the segment from Aug. 27.)