Home Canning - How Canning Preserves Foods Home Canning - How Canning Preserves Foods
The high percentage of water in most fresh foods makes them very perishable. They spoil or lose their quality for several reasons:
- Growth of undesirable microorganisms- bacteria, molds, and yeasts,
- Activity of food enzymes,
- Reactions with oxygen,
- Moisture loss.
Proper canning practices include:
- Carefully selecting and washing fresh food,
- Peeling some fresh foods,
- Hot packing many foods,
- Adding acids (lemon juice or vinegar) to some foods,
- Using acceptable jars and self-sealing lids,
- Processing jars in a boiling-water or pressure canner for the correct period of time.
Collectively, these practices remove oxygen; destroy enzymes; prevent the growth of undesirable bacteria, yeasts, and molds; and help form a high vacuum in jars. Good vacuums form tight seals which keep liquid in and air and microorganisms out.
Extracted from the "Complete Guide to Home Canning." First published: January, 1993. Reviewed: June, 1998.
Courtesy of the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS)