How to safely preserve premade soups

Premade soups make perfect meals on busy days during the fall and winter months. Who doesn’t enjoy a hearty soup or stew to warm up on cold days? They’re considered comfort food for a reason.

Incidentally, they’re also convenient food. Soups make excellent slow cooker meals that can be prepared in advance, so they’re ready at dinner time. If you prepare and store soups in advance, dinner through the week can be reduced to putting it in the slow cooker and bringing it up to temp before work and enjoying it when you get home.

Preserving premade soups

Any premade soup should be prepared with food safety in mind. Not every soup can be canned and stored for later use, as some ingredients interfere with the heat transfer during processing and can result in foodborne illness. In some cases, freezing is a better option, in others, canning some ingredients and adding others when heating the soup is preferable. The safest preservation method is determined by the ingredients of the soup you’re making.

Soups to can

Some soups can be preserved using home canning techniques. Most will take between 60 and 90 minutes to process in a pressure canner. The actual time is determined by the ingredients in the soup and the size of the jars being used. The list below describes which soups and ingredients are safe to can.

• Vegetable Soups. Vegetable soups with a simple broth base are safe to can. Fill each jar half full of solids. Then add broth, leaving 1 inch of headspace. Determine the processing time by using the processing time for the ingredient that takes the longest by itself.
• Vegetable meat soups. Vegetable soups with pieces of cooked beef or chicken are also safe to can. Just follow the same instructions you used to can vegetable soup.

Other canning tips

• Never use half-gallon containers to can soup.
• Don’t pack ingredients too solidly in jars. Leave enough space for hot liquid to circulate between solid food particles (vegetables and meat) during processing.
• Never add thickening agents to soups you plan on canning. Adding flour and other thickening agents prevents the contents in the center of the jar from being heated to a safe temperature to destroy bacterial spores that cause botulism.
• Never can soups that include butter, milk, cream, cheese or other dairy products. These low-acid foods should never be added to canned soups before being processed.
• Don’t add high starch products — noodles, alphabet noodles, spaghetti or other pasta, rice, barley — to soups before processing. They can interfere with heating your soup to a safe temperature during processing.
• Don’t can pumpkin, winter squash, broccoli or cauliflower soup. These soups contain ingredients that clump together and interfere with safe processing.

Adding ingredients later

• When canning a soup or stew that requires a thickening agent, wait until you are putting it in the slow cooker to add add flour, cornstarch or other thickening agent.
• Add butter, milk, cream cheese and other dairy products to soup when you’re putting it in the slow cooker.
• Add noodles, pasta, rice and other high starch products to canned soups and stews at serving time.

Soups to freeze

So how can you preserve all those creamed soups and soups that contain ingredients that aren’t suitable for canning? You can freeze them.

Freezing tips

• Freezing temperatures don’t kill bacteria, but bacteria can’t grow in the freezer.
• Use modified starches suitable for low temperatures to prevent thickened soups from separating.
• Although you cannot can pumpkin, squash, broccoli and cauliflower soups, they are flavorful when frozen.
• It is safe to freeze soups that contain pasta, rice or other high starch products; however, these products may become soft in freezer storage.
• Frozen soup should be thawed in the refrigerator to avoid foodborne illness. Only use the microwave to defrost it if you plan on eating it immediately after.

Resources

• Penn State Extension