Is your canning recipe safe?

There are unlimited resources for canning recipes such as cookbooks, websites, family recipe boxes, and more. Iowa State University Extension and Outreach recommends following scientifically researched and tested home canning recipes to ensure a safe, quality product.

The biggest concern with home canning is the prevention of botulism which can thrive in an oxygen-free, vacuum-sealed jar if the product has not been prepared or processed correctly. To avoid the potential of botulism, it is important to determine if the recipe is safe before gathering the ingredients and proceeding.

Is the recipe Generational or a Historic Recipe? Home food preservation is an ever-evolving science. The only safe home canning methods recognized today are processing in a boiling water bath, atmospheric steam canner, or pressure canner for a specified time. When used properly, these methods provide adequate heat to destroy harmful or spoilage organisms and drive air out of the jar for a strong vacuum seal. Recipes or instructions before 1994 are considered outdated unless formulations match new research-tested formulations.

Thickeners such as flour, starches, gelatin, pectin and even Clear Jel®, should not be used in canning recipes unless the recipe has been tested for such. Thickeners slow the rate of heat penetration into the product and may result in under processing and an unsafe product. Adding more processing time to accommodate the use of added thickeners is unsafe. Thickeners should be added to the product at time of use.

Added Ingredients? It is not safe to add extra ingredients to a recipe; adding beans or corn to a canned salsa recipe is not safe. It is also not safe to add extra vegetables to low-acid products, like extra onions, chilies, or peppers to tomato products or salsas. Additions may decrease the acidity and/or increase the density of the product resulting in an unsafe product.

Using current, research-based recipes from reliable sources is the best advice. The most recent USDA updates to home canning were made in 2015. Additional research has shown that elderberries and white peaches should not be canned due to safety concerns. Reliable canning resources include: