Update Canning Recipes

Do your recipes have a history?

• Some home canners use methods handed down through generations. Many of these practices were developed by trial and error; those that appeared to work were repeated. Therefore, if the jar sealed, it was assumed the food was safe. Unfortunately, this is not always the case. 
• Scientifically tested recipes have determined that adequate acidity exists to prevent spoilage when processed by a given method (boiling water bath, atmospheric steam canner, or pressure canner) for a specified time.
• Making changes in research-tested recipes risks food spoilage and puts people who eat the food at risk of foodborne illness.

Many people are using a favorite canning book that has a history. Maybe it is the one that came with their canner in the 1970s or earlier, or was handed down by a grandparent, or they are using the recipes from the canning chapter of a community cookbook. Indeed, they may have some flavorful recipes, but are they safe?

Most processing times in books published before 1994 are inadequate to control spoilage organisms. In the late 1980s, research was done to revise previously published USDA publications.

Changes to Historical Methods

• Many of the updated process times are longer to ensure that adequate heat penetrates the coldest part of the jar and is hot enough to destroy spoilage organisms.
• Some old methods were replaced.  It is no longer acceptable to pour hot jams, pickles, or relishes into the jar and just wait for the lid to "pop." Today, we know it is necessary to process these products in a water bath canner or an atmospheric steam canner to destroy microorganisms in the headspace and to create a strong vacuum seal.
• Older books do not include acidifying tomatoes to control botulism poisoning.
• Keep your old canning books as souvenirs or family treasures, but seek out newer research-tested recipes for current canning needs.

Use research-tested recipes that are 1994 or more recent. The more recent the canning book, the more likely it is to include the latest home food safety recommendations. There have not been major changes since 1994, but there are continually new research discoveries. The latest updates of the Let's Preserve fact sheets include warnings not to can white peaches or elderberries. A few recipes from the 1994 books have been withdrawn. A few years ago, new research indicated atmospheric steam canning for high-acid foods was acceptable if the correct procedures were followed. Therefore, a recent canning book is desirable.

Consider the Source of Recipes

Unfortunately, there are some newly published canning books and lots of internet canning recipes and videos that are not based on scientific research and don't contain safe methods.

References:

Ingham, B.H. (2020, August 24). "An Update on Safe Use of Steam Canners". University of Wisconsin, Madison.

LaBorde, L.  (2023, March 5).  "Canning and Freezing Questions and Answers". Penn State University.

Zepp, M., Hirneisen, A. & LaBorde, L. (2023, March 1).  "Let's Preserve Basics of Home Canning". Penn State University.