Canning

Open can of green beans

Canning is a method of food preservation in which food is processed and sealed in an airtight container, including but not limited to jars and cans. Canning can provide a shelf life of one to five years, although under specific circumstances, it can be much longer. A freeze-dried canned product, such as canned dried lentils, could last as long as thirty years in an edible state. Canning can also be used to preserve foods over much shorter timescales, from several days to several weeks.

Materials needed

For modern-style canning:

• Glass, for mason jars
• Some kind of metal for a strong lid
• Rubber or Wax for sealing
• A large pot of or pressure canner
• A jar-lifter
• Clean towels

For Potted-style canning:

• Small clay pots, often portion-sized
• Solid fat, such as clarified butter or tallow
• Optionally, cloth to cover

Crafting instructions

There are two main methods for modern canning; water bath canning (for high-acid foods) and pressure canning (for low-acid foods).

Water bath canning

1. Sterilize jars by boiling or washing in hot, soapy water.
2. Fill jars, leaving appropriate headspace (1/2" to 1")
3. Wipe rims and apply lid
4. Submerge jars in boiling water (must cover jars by 1–2 inches)
5. Process jars for the time specified in a recipe (depends on altitude/food).
6. Remove jars with a jar lifter, place on a towel, and let cool 12–24 hours.
7. Check seals—press the center of the lid; it should not pop up.
8. Store sealed jars in a cool, dark place. Refrigerate any unsealed jars.

Pressure Canning

1. Sterilize jars by boiling or washing in hot, soapy water.
2. Fill jars, leaving appropriate headspace (1/2" to 1")
3. Wipe rims, apply lid
4. Place jars in the pressure canner with the recommended amount of water.
5. Seal canner and vent steam for 10 minutes before applying pressure weight.
6. Process at pressure (usually 10–15 PSI) for the time your recipe calls for.
7. Let pressure drop naturally before opening.
8. Remove jars, cool, check seals, and store.

Potted Canning

The food to be preserved, often fish or meat, is placed in the clay dish and fat is added. The pot is then baked in an oven until cooked. More fat is added to completely cover the food, and is baked again to sterilize. When cool, the solid fat will create an airtight container that can last until the seal is broken or the fat becomes rancid. A cloth can be tied around the pot to delay spoilage.

Dependencies

• Steel
• Glass
• Tin
  • Canning
    • Food

See also

• Food preservation
• Pot-in-pot refrigerator
• Refrigeration

References

This article uses material from the Wikipedia article Canning, which is released under the Creative Commons Attribution-ShareAlike 3.0 Unported License (view authors).

External links

• Andress, Elizabeth; Kuhn, Gerald. (1998rev.) "II. Early History of USDA Home Canning Recommendations". Critical Review of Home Preservation Literature and Current Research. University of Georgia
• Andress, Elizabeth. (2014rev.) "II. Using Boiling Water Canners". Preserving Food: Using Boiling Water Canners. Athens, GA: University of Georgia, Cooperative Extension.
• Absorption refrigerator. Wikipedia, The Free Encyclopedia.