Refrigerating Tomato Paste Cans

• Refrigerating open cans of any food is a perfectly safe practice, notes U.S. Department of Agriculture Food Safety and Inspection Service. Refrigeration counters the growth of bacteria associated with foodborne illnesses, such as salmonella, which thrive in warmer temperatures. Covering it with foil or plastic wrap and refrigerating open cans of perishable items further prolongs their shelf life and freshness.

How Long to Keep Open Cans

• Despite the harmlessness of refrigerating an open can of tomato paste, it's still best to use the remaining product within one to two days. Tomatoes are acidic, and this acid continuously reacts with the can's material, typically aluminum or tinplate steel. These reactions, aided by oxygen, cause the can's material to oxidize, corrode and leach into the tomato paste. The result is a tinny flavor that permeates whatever you add the tomato paste to. If possible, put the tomato paste in a plastic or glass container before you put it in the refrigerator.

Storing Tomato Paste for Longer

• Freezing is the most effective way to store tomato paste from a can for more than a few days. To freeze, scoop tablespoons of tomato paste onto a cookie sheet lined with freezer paper or wax paper. After the dollops freeze solid, transfer them to a freezer bag or freezer container. Now you're free to use a tablespoon of tomato paste as you require. The frozen paste will keep fresh for approximately two months.

Buying Tomato Paste

• Preventing the spread of foodborne illnesses begins at the grocery store. When buying canned tomato paste, steer clear of dented, rusted, bulging or leaking cans. If you discover such a can in your pantry, throw it away. Double-bag the can and tie the bags tightly and place the bagged can in a trash can outside your home.