There has been more research attention given to the use of Atmospheric Steam Canners recently and several reliable sources are now stating that it is indeed safe to use them under certain circumstances as an alternative to a Water bath canner. Our local experts from the Penn State Extension Office shared this information in their most recent Newsletter and the local newspaper Lancaster Online recently covered this news and has created a wonderful video in which Marth Zepp walks you through the process of using a Steam Bath Canner and touches on some important reminders.
If you’re close to the Lancaster Area, you may want to attend the Workshop on Steam Canning in June!
“An atmospheric steam canner can be an alternative to a boiling water canner. Use a steam canner only to process high acid foods such as peaches, pears, and apples, or acidified foods such as pickles and relishes. Foods must be high in acid with a pH of 4.6 or below.
Use a research tested recipe developed for a boiling water canner from an approved source such as USDA recipes or from Penn State Extension. The booklet accompanying an atmospheric steam canner can’t be relied on to provide safe canning instructions or process times.
Use standard canning jars with 2-piece metal lids.
Jars must be heated prior to filling just as in other forms of processing.
A rack should be in the base of the canner to lift the jars above the water.
Fill the base of the steam canner with 2 to 2½ quarts of water. Heat. As each jar is filled, place it on the rack and replace the cover until all jars are filled.
Jars must be processed in pure steam at 212°F. Watch for venting prior to starting the processing time. Turn the heat on high under the canner, and watch for a full column of steam 6 to 8 inches long flowing from the vent hole(s). Once you see full venting, begin timing the process. Steam has to flow freely from the canner vent(s) during the entire process or the food is considered under-processed and unsafe.
Regulate burner heat so that the canner maintains a steady flow of steam and a temperature of 212°F. A canner that is boiling too vigorously can boil dry within 20 minutes. If a canner boils dry, the canner can be damaged and the food is considered under-processed and potentially unsafe.
Adjust processing time for higher elevations as required by a tested recipe.
Processing time must not exceed 45 minutes including any modification for elevation because the canner could boil dry.
Do not open the canner during processing— steam will escape and the temperature will be lowered.
When processing time is complete, remove the lid. Allow jars to sit in the canner for five minutes; then remove to a towel covered counter away from drafts. Allow jars to cool naturally—don’t force cool jars.
Before canning your first load of food, do a dry run to practice maintaining a steady stream of steam.
As with any canning, steam will be produced. It is best to have adequate ventilation to allow excess steam to escape from the room.”
The National Center for Home Food Preservation also put out a statement on the practice.
You can find the full Let’s Preserve Newsletter from our local Penn State Extension Office which includes many other tips on preserving and food safety here.