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.

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

Open Kettle Canning - Iowa State University
Canning Equipment Information - Kansas State University

Did You Know?

Do not taste food from a jar with signs of spoilage!

Unsafe Canning Practices