Safe at home: Extension experts guide Ohioans through food preservation season

COLUMBUS, Ohio - That jar of homemade jam or crunchy home-canned green beans might look delicious on the pantry shelf, but if it wasn't preserved using tested, science-backed methods, it could pose serious health risks.

Improper food preservation techniques can lead to the growth of harmful pathogens, including Clostridium botulinum, the toxin that causes botulism, a potentially fatal illness. To help Ohioans preserve food safely this season, Ohio State University Extension is offering a suite of free webinars, hands-on pressure canner testing, and science-based resources across the state.

Kate Shumaker, an OSU Extension educator and registered dietitian, leads the statewide Extension Food Preservation Team. Together, the team provides trusted guidance to help families stretch their harvests while protecting their health. OSU Extension is the outreach arm ofThe Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES).

"Preserving food at home can be a great way to enjoy the harvest year-round," Shumaker said. "But it's important to follow tested recipes and guidelines to prevent spoilage - and to avoid dangerous foodborne pathogens."

Among the most common mistakes? Using outdated or unverified recipes, overtightening lids, and skipping critical steps such as adjusting for elevation or measuring the correct headspace in jars.

"We often see people using recipes found online or passed down through family without knowing whether they've been validated for safety," Shumaker said. "That can create serious risks."

Nicole Arnold, assistant professor and food safety field specialist with CFAES, emphasized the importance of following recipes from trusted sources - such as the U.S. Department of Agriculture, OSU Extension, or the National Center for Home Food Preservation.

"Recipes that haven't been tested may allow for the growth of Clostridium botulinum," Arnold said. "It's a paralyzing and potentially fatal illness that's caused by a tasteless, odorless, and invisible neurotoxin. Even a tiny amount of the toxin can be deadly."

Arnold also cautioned consumers about a recent trend: vinegar with only 4% acidity, sometimes sold near canning supplies. Only 5% acidity vinegar is safe for canning.

"Always read the label," she said. "Using a vinegar with insufficient acidity can create an environment where pathogens can grow."

To support safe food preservation efforts, OSU Extension's Food Preservation Team offers the following.

• Webinars: A free series titled Trends and Traditions in Home Food Preservation runs July 15 through Sept. 9, with sessions every other Tuesday at noon. Topics include selecting and storing produce, canning, freezing, and drying.
• Pressure canner testing: Statewide appointments are available to ensure canning equipment is functioning safely. Sign up at go.osu.edu/pressurecannertesting.
• Fact sheets and how-to videos: Continuously updated for scientific accuracy and accessibility, these resources are available at ohioline.osu.edu.
• LiveSmartOhio Facebook tips: Weekly preservation tips and videos are shared at facebook.com/livesmartohio.

Shumaker noted a growing trend in at-home freeze-drying - especially among consumers looking to transform everyday produce into something entirely new.

"Freeze-drying can transform a sliced zucchini into a snack to rival potato chips - with as many flavor options," she said. "And the trend is growing fast."

But no matter the preservation method, safety must remain the top priority.

"This outreach reflects the broader mission of the college," Shumaker said. "Food preservation connects to sustainability, food security, safety, and agricultural viability. When done safely, it helps reduce waste, extends harvests, and supports resilient food systems."

The stakes go far beyond individual households. Left unaddressed, unsafe practices could strain public health systems, undermine confidence in local food production, and jeopardize Ohio's food and agricultural industries.

"It illustrates the critical nature of our work - particularly those that, if left unaddressed, would have significant implications for Ohio's producers, economy, and our industries in the future," Arnold said.

For more information or to register for a webinar, visit fcs.osu.edu/programs/healthy-people/food-preservation. In addition to the live series, over 40 recorded webinars are available to view anytime. To locate your county Extension office, visit extension.osu.edu/lao.