MSU Extension Food Preservation

Preserving soup for meals in the fall and the winter is a great way to have a hot meal on the table in minutes on a busy, cold day. A hot bowl of soup warms from the inside out, and if you have ingredients from your garden or farmers market, they can be economical as well. There are two ways to preserve soups: canning or freezing. 

The best soups to can or freeze are vegetable, chili, stock, bean, seafood, tomato or split pea soups.  Soups that cannot be canned are cream soups and soups with the following ingredients: pasta, rice, flour, cream, milk and other thickening agents. 

Most soups for canning consist of low-acid ingredients, so they must be pressure canned.  Low-acid foods (greater than 4.6 pH) include, all vegetables, mixed canned foods like soups with tomatoes, corn, and green peppers, meats, poultry and seafood.  If low-acid foods are canned in a water bath canner, they can be a source of a toxin that will cause botulism. The toxin can affect your nerves, cause paralysis and even cause death.  You never know what low-acid item is going to contain botulism; therefore, the only way to guarantee a safe recipe is by using a research-based recipe. 

No matter what method of canning or freezing you prefer, always follow good food safety practices. This means washing your hands for at least 20 seconds using soap and warm water before beginning canning or freezing, after using the bathroom, after smoking, after changing a dirty diaper, after taking out the garbage or anytime that you may have contaminated your hands. Keep your kitchen and equipment clean throughout your whole preservation process. 

If you are canning soups, always following a research-based recipe. Recommended sources for research-tested recipes include the USDA Guide to Home Canning, So Easy to Preserve, The Ball Blue Book Guide to Preserving or Cooperative Extension resources like the Michigan Fresh fact sheets from Michigan State University Extension.

Follow all canning instructions for your soup recipe including preparation of the ingredients, cooking the soup, preparing jars and lids, proper amount of head space, venting your canner, processing and cooling times and  labeling your product after it is completed. 

Freezing soup is a little easier and less time consuming than canning. Make your soup according to the recipe directions, and ladle into your containers. Containers may be wide-mouth canning jars or rigid plastic containers. Leave one inch of head space for quarts and ½ inch of headspace for pints to allow for expansion of the liquid during the freezing process. Cool the soup in the refrigerator before freezing.  Always label your product with the product name, amount and date before freezing. 

Take the soup out of freezer and thaw in the refrigerator a couple of days before using it to allow it to come out of the container easily. 

Cook your soups until boiling and heated throughout the container on the stove top or in a microwave. Check the temperature to be sure it is at least 165 degrees Fahrenheit.  Serve with a thick crusty bread for a tasty cold weather meal. 

If you need to increase the quantity of the soup, add broth, such as diced or shredded meat and a small amount of pasta or rice. Allow extra cooking time if you are adding extra ingredients. If adding uncooked rice (about 1/3 cup) to your soup, add an extra 20 minutes to the cooking time to cook the rice.  Uncooked pasta will increase cooking time about ten minutes.