- 1 The definition of pressure canning
- 2 Pressure Canner History
- 3 Pressure canner brands
- 4 Further Reading
- 5 Pressure Canning Information
- 5.1 Can I just pressure can everything instead of water bathing?
- 5.2 Dirty lids after pressure canning
- 5.3 Minimum jar load for pressure canners
- 5.4 Mirro Pressure Cooker & Canners Instructions Manual & Recipe Book
- 5.5 Pressure Canner Altitude Adjustments
- 5.6 Pressure Canner Brands
- 5.7 Pressure Canner Gaskets
- 5.8 Pressure Canner Heat Source
- 5.9 Pressure Canners: Dial Gauge or Weighted Gauge?
- 5.10 Pressure Canners: When size matters
- 5.11 Pressure Canning Fish and Seafoods
- 5.12 Pressure Canning Principles
- 5.13 Pressure Canning Step-by-step
- 5.14 Pressure Cookers versus Pressure Canners
- 5.15 Pressure Gauge Testing
- 5.16 Presto Canners
- 5.17 Presto Pressure Canner 3-piece Regulator Weight
- 5.18 Presto Pressure Canner Accessories
- 5.19 Presto Pressure Canner Gauge Testing
- 5.20 Presto Pressure Canner Manual
- 5.21 Presto Pressure Canner Replacement Rings / Gaskets
- 5.22 The cool down process is important in pressure canning
- 5.23 Why is 10 pounds and not 15 pounds the base for pressure canning?
The definition of pressure canning
Pressure canning is one of the two methods used for home preservation of food in jars.
Pressure canning involves sealing food in jars, then putting the jars into a large, pressurized pot that raises the temperature of the food products inside the jar far above boiling for a given period of time. Typically, home pressure canning is currently done at 115 C (240 F).
Three things are done to the jars as a result of this simple process: 1
- Removal of oxygen: The jar expels any oxygen inside it which could spoil food;
- Heat sterilization: Any nasties that could interfere with food safety are killed off;
- Sealed jar: As a result of the expelled air, a vacuum seal is created inside the jar so that nothing can re-enter the now sterile environment inside the jar.
Pressure Canner History
Pressure canners for a time had a competing technical: adding calcium chloride (which is now used to crisp pickles) to the water instead to raise the temperature:
[Appert] did experiment with pressure processing, but at that time ‘digesters’ were quite dangerous, and it was not the norm. Around 1863 processors used ‘chemical baths’, in which high concentrations of calcium chloride enabled ‘water’ to boil at up to 121 C. This allowed for significantly shorter cooking times. By 1870 basic retorts were being used to temperatures up to 121 C but they were still quite dangerous and hand operated.” 2
During World War Two, pressure canners in America were limited by rationing.
A limited number of pressure canners – the size to process seven quarts at one time — are being manufactured and distributed by rationing. There are not nearly enough steam pressure canners to go around. But if individuals and groups owning canners share them and keep them working at capacity, steam pressure canners will preserve millions of jars of food. If you have no steam pressure canner, team with someone who has. Or go to a community food preservation center. Or if you would make extra good use of a canner, apply through your county farm rationing committee to buy one.”3
Pressure canner brands
See separate page dedicated to pressure canner brands.
Utah State University Cooperative Extension. General information about pressure canners (Link valid as of spring 2015.)
Pressure Canning Information
Andress, Elizabeth. “History, Science and Current Practice in Home Food Preservation.” Webinar. 27 February 2013. [42:00] Accessed January 2015 at http://nchfp.uga.edu/multimedia/video/nchfp.wmv ↩
Featherstone, Susan. A Complete Course in Canning and Related Processes: Volume 2. Cambridge, England. Woodhead Publishing. 2014. Page xxxi. ↩
Wartime Canning of Fruits, vegetables. USDA Bureau of Human Nutrition and Home Economics. Washington, DC. June 1943. ↩