Official home food preservation guidelines, available online at the National Center for Home Food Preservation, are periodically updated, Carter said. So, if you are following old guidelines, you aren’t getting the most accurate information. For example, tomatoes used to be considered a high-acid food, but today’s varieties are often right on the line between high-acid and low-acid, so citric acid or vinegar must be added to them before being canned. Also, standard household vinegar is now often at a lower strength than it used to be, Carter said, so following old recipes, possibly passed down for generations, that call for vinegar to acidify a food for water bath canning may not provide the margin of safety necessary.

Many people who have canned for years — even decades — are unaware of new recommendations, she said. And, surprisingly, she added, canning methods portrayed on televised food shows, websites, and even in some cookbooks are often improper. “People don’t know what they don’t know,” Carter said “So we’ve been trying to get information out to people. It’s important.” Deb Kilbarger, registered sanitarian and food program supervisor for the Fairfield Department of Health, said the April incident was the first time she and her colleagues, some of whom had worked in public health for decades, had seen a case of foodborne botulism, “let alone an outbreak.” The crisis made a lot of people sit up and take notice, said Kelly Spindler, registered sanitarian and director of environmental health for the department. “It helped people understand how serious food safety is, what can go wrong if food is not properly prepared or held at the proper temperatures, and, in canning, how important it is to follow certain procedures,” Spindler said. Aubry Shaw, of Grove City, attended two of Carter’s sessions this summer. She still misses her mother-in-law, Kim Shaw — the woman who died in the botulism outbreak. “She was always smiling,” Shaw said. “She was a wonderful mother. She was a great provider for the family. She would go out of her way to do anything for anybody. She was amazing.” The personal experience of losing someone to foodborne botulism drew Shaw — and her grandmother — to participate in Carter’s canning classes. “Even if you’ve had some experience in canning, there’s always something you can learn,” Shaw said. “That’s why it’s important to come to classes like this. I think food safety programs like this from the Extension office are incredible.” In fact, Kilbarger said, she knows of no other organization that offers home food preservation classes like Extension’s. “Anyone who cans should take the class,” Kilbarger said. “Even if you’ve been doing it forever, there might be a safer way. Hopefully, these classes will prevent anything like this from happening again.” Shaw provided an additional word of guidance: “If you home can, just be safe about it. If you have canned something and it doesn’t seem quite right, just throw it out. It’s not worth taking a chance.” (To sign up for a free subscription to Food Safety News, click here.)