Burning Issue: Using Atmospheric Steam Canners
Can acid foods be processed in steam canners?
The University of Wisconsin, under the leadership of Dr. Barbara Ingham, has conducted research on appropriate use of atmospheric steam canners for home canning in collaboration with the National Center for Home Food Preservation (NCHFP). Atmospheric steam canners are used for processing naturally acid or properly acidified foods with natural or equilibrated pH values of 4.6 or below. They are not pressurized vessels used for processing for low-acid foods.
Sufficient studies and peer review have been completed that we are now able to say that as long as certain critical controls at various steps in the canning process are achieved, USDA and NCHFP process times for canning acid or properly acidified foods (pH of 4.6 or below) at home with properly research based recipes and procedures can be used. The research looked at temperature distribution in the steam environment surrounding the jars in a dome-style steam canner, heating patterns of several different food types during processing in the canner, and the contribution of standardized cooling procedures at the end of the process time.
The results of this research were published in a peer-reviewed scientific journal in May 2015.
Willmore, P, Etzel, M, Andress, E. and Ingham, B. (2015). Home processing of acid foods in atmospheric steam and boiling water canners. Food Protection Trends, Vol 35, No. 3 (May-June), p.150–160.
September 9, 2015
National Center for Home Food Preservation