General Information
The practice of preserving food has existed for thousands of years. Because food starts to spoil as soon as it is harvested, preservation methods helped keep the food for longer periods of time. This allowed ancient people to live in one place for longer periods of time.
Today, food preservation has transformed from a rural practice of being self-sufficient to a practice of preserving for fun. Gardening is a popular activity and farmer's markets are sprouting in many communities. Abundant fresh vegetables and fruits motivate consumers to save summer tastes for other times of the year.
Let's learn about food preservation and how to use today's modern methods to preserve food safely.
- Canning - University of Georgia
- Freezing - University of Georgia
- Pickling and Fermenting - University of Georgia
- Jams, Jellies, and Marmalades - University of Georgia
How Temperature Affects Food Preservation
Temperatures for Food Preservation
| Temperature | Effect |
| 240 to 250oF | Pressure canning temperature for low acid vegetables, meat, and poultry. |
| 212oF | Boiling-water canner temperature for acidic fruits, tomatoes, pickles, and jellied products |
| 180 to 250oF | Canning temperature that destroys most bacteria, yeasts, and molds in acidic foods. As temperature increases, the destruction time decreases. |
| 140 to 165oF | Warming temperatures prevent growth, but some microorganisms survive in this range. |
| 40 to 140oF | TEMPERATUREDANGERZONE! Rapid microbial growth occurs in this range. |
| 95oF | Maximum storage temperature for canned food. |
| 50 to 70oF | Best storage temperature for canned and dried foods. Keep area cool, dry, and dark. |
| 32oF | Temperature water freezes. |
| 32 to 40oF | Microorganism growth slows, but they are not killed. |
| 0 to 32oF | Microorganism growth stops, but they are not killed. |
| 0 to - 10oF | Best temperature for storing food in a freezer. |
Canning Equipment
When current food preservation recommendations are followed, home preserved foods can be very safe. Here are some older preservation practices no longer recommended.
- Unsafe canners and canning methods - Penn State University
- Open Kettle Canning - Iowa State University
- Jars with wire balls and glass caps - University of Georgia
- Canning Breads and Cakes - University of Georgia
- Using paraffin wax on sweet spreads - University of Georgia
- Canning in Pressure Cookers - University of Georgia
- Canning Pumpkin Butter and Mashed or Pureed Squash - University of Georgia
- Canning Chocolate Sauce Unsafe - University of Georgia
Did You Know?
Do not taste food from a jar with signs of spoilage!
Unsafe Canning Practices
- Using Boiling Water Canners
- Using Pressure Canners
- Buckled or Creased Lids
- Principles of Home Canning