Regional Extension Agent Angela Treadaway

Regional Extension Agent Angela Treadaway

How many of you remember as a child growing up and having your mother or grandmother open a can of home preserved vegetable soup and how it made the coldest of winter days seem warm? 

August and September are the best months to prepare soup, because there should be such an abundance of fresh vegetables. Preparing your own soup in the summer can do just that for you in the winter.

As a Regional Food Safety and Quality agent with the Alabama Cooperative Extension System, I have clients who call asking questions about making soups at home and preserving them for their family for the winter months. 

The problem a lot of times is where they may have gotten their recipe from: grandmother from years ago, online or they just made one up they really like and think it would be good to can it. 

They want to just make the soup, cook it, fill jars, and then process in a water bath canner or pressure canner for just about 15-20 minutes. 

They feel like if I cooked it, it really doesn’t matter how long I preserve it. 

Not a good idea at all. 

You want to use tested USDA recipes that have a tested process time to go along with it. You can do a base soup or broth and then add other items when you open it to prepare in the winter months.

Problem Ingredients in Home Canned Soups

Do not add noodles, other types of pasta, rice, flour, cream, milk, or other thickening agents to soups and stews before canning. 

Adding flour or other thickening agents to a product for home canning prevents the heat from penetrating to the center of the jar interfering with safe processing to destroy the bacterial spores that cause botulism. 

Never add thickening agents to a home canned product. Wait until you are ready to prepare the food for serving and then add the flour, cornstarch, or other thickening agent you are using.

Butter, milk, cream, cheese and other dairy products are low acid foods that should never be home canned. 

Again, add butter and milk to soup just before serving. Products high in starch also interfere with heat processing. Thus, add noodles or any type of pasta, rice, or dumplings to canned soups or stews at serving time.

What Soups Can be Preserved at Home?

Vegetable soups in a broth base may be safely canned using the process time for the ingredients that takes the longest process time for the individual ingredients in the soup. 

Most soups will take 60 to 90 minutes to process in a pressure canner, depending upon size (pints or quarts) and ingredients. 

Never can soup in half-gallon containers. 

Use caution to avoid packing ingredients too solidly in the jars. For vegetable soup, fill the jars half full of solids, add broth allowing 1-inch headspace and process in a pressure canner. There needs to be space for the hot liquid to circulate between the food particles. 

Pieces of cooked beef or chicken can be added to the vegetables to make a vegetable meat soup. Thickened or creamed tomato soup should not be canned. Instead, can tomato juice, tomato vegetable juice blend, or crushed tomatoes (without added vegetables). 

When you want to make the soup, open the jar of tomato product, add whatever seasoning vegetables and thickeners, desired. A good cream of tomato soup is made by pouring the heated tomato mixture into a heated white sauce.

Avoid canning pumpkin, winter squash, broccoli, or cauliflower soup. These pack together and contain ingredients that interfere with safe processing. There is no scientifically research tested recipes for these soups.

How can you preserve soup safely? Freeze it. 

Although freezing temperatures do not kill bacteria, microbial growth stops in the freezer. Using a modified starch suitable for low temperatures such as ThermFlo® will help prevent separation of a thickened soup. 

Soups made from fall vegetables such as pumpkin, butternut squash, cauliflower, or broccoli are flavorful when frozen. 

It is also safe to freeze vegetable and meat soups that contain pasta, rice, or noodles. 

Just remember to allow time for frozen soup to thaw in the refrigerator; or if it is defrosted in the microwave oven, it should be heated and eaten immediately.

Saving Money and Controlling Ingredients

The great thing about preserving your own soups and stews at home, especially if you grow your own vegetables, you can save money, and control the ingredients, seasonings and salt. 

Many commercial soups have lots of salt which is not good for those of us limiting our sodium intake. 

Salt is optional in canning soups. It is used for seasoning and does not help to preserve the food.

Processing: Why Do I Need to Use a Pressure Canner?

High-acid food (those with a pH of 4.6 or lower) contain enough acid to help control the growth of harmful bacteria and can be safely processed in a boiling water canner. 

However, all meats and vegetables are low-acid foods, with pH levels ranging from 4.9 to 7.3. They do not contain enough acid to prevent the growth of the bacterium, Clostridium botulinum, which produces the toxin that causes botulism. 

For soups and stews, the high temperature of 240° for a certain amount of time (this temperature can only be reached in a pressure canner) is necessary to destroy any spores of Clostridium botulinum that might be present. Pressure canning correctly can prevent these spores from growing into bacterial cells in the canned jars of soups and stews.

More Info on Safe Home Canning and Canning Recipes

Please visit www.aces.edu and in the search bar or under the food safety link look for Wise Methods of Canning Vegetables or our other canning publications. 

For more soup and stew recipes that are USDA tested please visit the National Center for Home Food Preservation website at https://nchfp.uga.edu/ 

Canning Soups and Stews Free Virtual Class

A FREE virtual canning soups and stews class will be taught by the Alabama Cooperative Extension Food Safety Team Thursday, Sept. 22, from 1-3pm.  

Please pre-register at this registration link to participate: https://www.aces.edu/go/preserve-soups.  

For more information about this class or other food preservation questions, contact Angela Treadaway at treadas@aces.edu or call 205-410-3696.