Click Here to read their article.
Safe Preserving: Using an Atmospheric Steam Canner
Posted on June 24, 2015 by Barb Ingham
Here are the guidelines for using an Atmospheric Steam Canner for Home Food Preservation as posted by Dr. Barbara Ingham, bhingham@wisc.edu
Victorio Steam Canners with built-in temperature gauge Image credit: victorio.info
June 2015
The University of Wisconsin-Madison has published research which indicates that an Atmospheric Steam canner may be used for home canning of naturally acid foods such as peaches, pears, and apples, or acidified-foods such as salsa or pickles, as long as all the following criteria are met:
• Foods must be high in acid, with a pH of 4.6 or below. Either a Boiling Water Canner or an Atmospheric Steam Canner can be used to safely preserve foods high in acid.
• A research tested recipe developed for a boiling water canner must be used in conjunction with the Atmospheric Steam Canner. Approved recipes are available from sources such as the National Center for Home Food Processing and Preservation: nchfp.uga.edu Standard canning jars with 2-piece metal lids must be used. The booklet accompanying an Atmospheric Steam Canner can’t be relied on to provide safe canning instructions.
• Jars must be processed in pure steam at 212°F. The canner must be vented prior to starting the processing time until a full column of steam appears. A full column of steam (6-8 inches) should be observed venting from the hole(s) in the side of the canner during the entire timed process. Ideally, temperature should be monitored with a thermometer placed in the vent port, but the placement of jars in the canner may make this difficult. Some appliances come with a built-in temperature sensor in the dome lid and these appear to be accurate.
• Jars must be heated prior to filling, and filled with hot liquid (raw or hot pack). An Atmospheric Steam Canner can be used with recipes approved for half-pint, pint, or quart jars.
• Processing time must be modified for elevation as required by a tested recipe. Elevation for any address can be checked here: http://www.daftlogic.com/sandbox-google-maps-findaltitude.htm
• Processing time must be limited to 45 minutes or less, including any modification for elevation. The processing time is limited by the amount of water in the canner base. When processing food, the canner should not be opened to add water. Regulate heat so that the canner maintains a temperature of 212°F. A canner that is boiling too vigorously can boil dry within 20 minutes. IF a canner boils dry, the food is considered under-processed and therefore potentially unsafe.
• Cooling of jars must occur in still, ambient air. Cooling is important for safety. Jars should be cooled on a rack or towel away from drafts. Jars should not force-cooled.
The University of Wisconsin-Madison has published research which indicates that an Atmospheric Steam canner may be used for home canning of naturally acid foods such as peaches, pears, and apples, or acidified-foods such as salsa or pickles, as long as all the following criteria are met:
• Foods must be high in acid, with a pH of 4.6 or below. Either a Boiling Water Canner or an Atmospheric Steam Canner can be used to safely preserve foods high in acid.
• A research tested recipe developed for a boiling water canner must be used in conjunction with the Atmospheric Steam Canner. Approved recipes are available from sources such as the National Center for Home Food Processing and Preservation: nchfp.uga.edu Standard canning jars with 2-piece metal lids must be used. The booklet accompanying an Atmospheric Steam Canner can’t be relied on to provide safe canning instructions.
• Jars must be processed in pure steam at 212°F. The canner must be vented prior to starting the processing time until a full column of steam appears. A full column of steam (6-8 inches) should be observed venting from the hole(s) in the side of the canner during the entire timed process. Ideally, temperature should be monitored with a thermometer placed in the vent port, but the placement of jars in the canner may make this difficult. Some appliances come with a built-in temperature sensor in the dome lid and these appear to be accurate.
• Jars must be heated prior to filling, and filled with hot liquid (raw or hot pack). An Atmospheric Steam Canner can be used with recipes approved for half-pint, pint, or quart jars.
• Processing time must be modified for elevation as required by a tested recipe. Elevation for any address can be checked here: http://www.daftlogic.com/sandbox-google-maps-findaltitude.htm
• Processing time must be limited to 45 minutes or less, including any modification for elevation. The processing time is limited by the amount of water in the canner base. When processing food, the canner should not be opened to add water. Regulate heat so that the canner maintains a temperature of 212°F. A canner that is boiling too vigorously can boil dry within 20 minutes. IF a canner boils dry, the food is considered under-processed and therefore potentially unsafe.
• Cooling of jars must occur in still, ambient air. Cooling is important for safety. Jars should be cooled on a rack or towel away from drafts. Jars should not force-cooled.
Download and Print guidelines for using a steam canner by clicking one of these links. (Wisconsin (word) (pdf); all other states (word)(pdf)).
Click HERE to read a PDF version of the guidelines for using a Steam Canner for all states other than Wisconsin.
This is an email that was sent by Elizabeth Andress from the NCHFP concerning the Steam Canner.
"There is no official NCHFP statement on using atmospheric steam canners at this point. As long as you are able to meet the requirements that Dr. Ingham at University of Wisconsin has published/presented, then you should be able to use them to process acid or properly acidified foods using the USDA process times. But all her conditions should be met -- for example, (I don't have the whole list here but they are in her blog article): measuring the temperature of flowing steam inside the dome before starting the process time, no process time longer than 45 minutes, do not open the canner during any of the process time, etc. Right now, people are free to use Dr. Ingham's advice from the University of Wisconsin. It will take us some time to have an official set of directions from the NCHFP on our website, but this research was conducted in cooperation with our project, and I support her findings."
Update from NCHFP: They have now put their seal of approval on using the Steam Canner
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.
Click HERE to read the entire article from NCHFP.
This is an email that was sent by Elizabeth Andress from the NCHFP concerning the Steam Canner.
"There is no official NCHFP statement on using atmospheric steam canners at this point. As long as you are able to meet the requirements that Dr. Ingham at University of Wisconsin has published/presented, then you should be able to use them to process acid or properly acidified foods using the USDA process times. But all her conditions should be met -- for example, (I don't have the whole list here but they are in her blog article): measuring the temperature of flowing steam inside the dome before starting the process time, no process time longer than 45 minutes, do not open the canner during any of the process time, etc. Right now, people are free to use Dr. Ingham's advice from the University of Wisconsin. It will take us some time to have an official set of directions from the NCHFP on our website, but this research was conducted in cooperation with our project, and I support her findings."
Update from NCHFP: They have now put their seal of approval on using the Steam Canner
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.
Click HERE to read the entire article from NCHFP.