I’d like to learn how to can to stock up my pantry and save money on food, but I’m scared of botulism. How common is botulism in home-canned goods? What do I need to know to can safely?
Home canning involves heating food in jars to a temperature that destroys microorganisms that cause food spoilage or health issues. Air is driven from the jar during this process, and as it cools, a vacuum is formed that prevents air (which may be contaminated with microorganisms) from reentering. Canning is one of the most groundbreaking food-preservation discoveries in history, but it must be done correctly to be safe.
The biggest danger with using unsafe canning methods is the risk of botulism. The bacteria Clostridium botulinum thrives and creates a deadly toxin in low-oxygen environments, such as home-canned food. According to the Centers for Disease Control and Prevention (CDC), “Botulism is a rare but serious illness caused by a toxin that attacks the body’s nerves. Botulism causes difficulty breathing, muscle paralysis, and even death.”
There’s bad news and good news about botulism. The bad news is that, as the CDC says, the toxin produced by botulism can be deadly. That’s why you don’t want to risk it by using bad canning practices. The good news is that it’s easy to avoid botulism in canning by following the rules.
Safe canning practices have evolved as our knowledge has evolved. One of those discoveries is that low-acid foods (including all meats and plain vegetables) must be pressure canned. No exceptions. (You can water bath can pickled and fermented vegetables as long as you follow proper guidelines.) When you break the rules because you think they don’t apply to you, then you risk botulism. For this reason, keep an up-to-date canning reference by an authoritative source. For novices, I recommend the U.S. Department of Agriculture’s Complete Guide to Home Canning or the (less comprehensive) Ball Blue Book.
Here are safe canning rules in a nutshell:
- Canning is divided into two categories: water bath canning (for high-acid foods, including most fruits) and pressure canning (for low-acid foods, such as meats and plain vegetables). Proper canning requires proper equipment, including jars, lids, rings, pots, racks, and ancillary equipment, such as a wide-mouthed funnel and a jar lifter. For pressure canning, a pressure canner is required. (A pressure canner isn’t the same thing as a pressure cooker.) The biggest mistake canners make, either from ignorance or defiance, is to use the water bath method to can foods that should be pressure canned, because “that’s what Granny always did.”
- In addition to choosing the right canning method for the food you’re preserving, follow the proper processing guidelines. These guidelines change with altitude; people living at sea level and people living in mountainous terrain have slightly different requirements (either a longer time in the water bath, or higher pressure in the pressure canner). All canning reference guides will include charts and tables to explain these differences.
- Never take shortcuts when canning. Dangerous shortcuts include modifying processing times or pressures. (“I’m in a hurry, so I’ll only pressure can my green beans for 10 minutes. What could go wrong?”)
- Never engage in dubious canning practices, such as dishwasher canning, oven canning, open-kettle canning, dry canning, or (as belabored previously) water bath canning low-acid foods. No matter who tries to convince you otherwise, these methods are never safe.
That said, as the CDC confirms, botulism is rare – in the United States, approximately 25 cases of foodborne botulism are reported each year. In 2019, of the 21 foodborne botulism cases reported, three deaths occurred. So, while botulism can be dangerous, if you carefully follow canning guidelines, you can rest assured that the food you’re putting up will be safe for your family to eat.
When canning, pick a day when you aren’t distracted or multitasking. Instead, focus, relax, and learn to enjoy the process. I’m invariably tired but stoked after a day of canning. There’s nothing prettier than jewel-bright jars of home-canned foods cooling on the kitchen counter. Done correctly, canning is truly a homesteader’s joy.
