What You Need to Know About Home Canning and Food-borne Illness Prevention

It is the time of the year when all the hard work of planting, weeding, and watering come to fruition. Now, what can you do with the bountiful harvest that your garden has put forth? There are many options for you to save your harvest, including freezing, canning, fermenting, or drying.  In today’s blog, we are going to explore canning, and how you can avoid a foodborne illness such as botulism while preserving your harvest. These are not the steps to follow when you are canning, but a general overview for you to stay safe while you are canning and consuming home-canned foods.

First, you will need a canner, and the type of canner you will need to use will depend on what you will be canning.  There are two types of canners, water-bath canners and pressure canners. Please do not use your high-pressure cookers that have become so popular over the last few years to can your produce.  They are not meant for canning.  Water-bath canners are great for canning tomatoes, spaghetti sauces (without meat) sauerkraut, pickles, and salsas, or anything that has a high acid content.  Pressure canners are used for canning meat and poultry, low acid foods such as green beans, corn, potatoes, and fish. Make sure that they are the right size and in good condition because canners that are too small will not cook properly. Double-check all the vents and gaskets to ensure that the canner will seal properly. (1)

Next, you will need to have a recipe that has been scientifically tested. Many recipes that are handed down or found in old cookbooks are no longer relevant due to the equipment that we now use to can is different than what our grandparents used in the past. Recipes that have been tested can be found in the Complete Guide to Home Canning at https://nchfp.uga.edu/publications/publications usda.html. The FDA website has many canning hints and ideas as well as safety tips as well. Manufacturers of canners and jars also have tested recipes that you may use. (1), (2)

Jars, lids, and seals must be scrutinized to ensure that there are no defects, such as cracks or chips in the jars that you will be using. Only use jars that are made to withstand the heat and pressure of canners.  Do not use old mayonnaise or peanut butter jars to preserve your tomatoes! Make sure that the rings that you are using are not dented or rusted, and the lids are new unless they are specifically made for reuse. Jars and lids need to be sterilized for jams and jellies prior to use, but for all foods, they need to be clean.  Follow the manufacturer’s directions for cleaning, using and/or sterilizing jars and lids. When sealing the jars, make sure that the lids and rims of the jars are free from food or liquids. Jars that have food or liquids on the rims or lids will not seal properly. If the jar does not seal, the food is still good to eat if you store it in the refrigerator until it can be consumed, or you can sometimes reprocess the jars.

Wash and inspect your produce to ensure that it is free from dirt and spoiled areas. You may cut off spoiled areas and use the rest of the unspoiled fruit or vegetables for canning.

Once your produce, meat, poultry, or fish is canned and you have made sure that the lids have sealed (they make a popping noise as they cool, and the lid cannot be depressed when you push on it), allow the jars to cool prior to storing them. Jars of fruits or produce need to be stored in a cool, dark place. When it is time to use your canned food, make sure that the jar is still sealed, and there is no discoloration. If the jar is cracked or damaged, make sure that you discard the contents.  Food that is foamy, discolored, slimy, moldy or has a bad odor means that the food has spoiled. DO NOT CONSUME IT. (1)

What illness can I catch from home-canned food?

Botulism is the most common food-borne illness from improperly canned food.  It is not just limited to the home canner but can also happen when manufacturing steps are skipped or equipment malfunctions in commercial operations. Botulism is caused by Clostridium botulinum which is found in the environment, commonly in soils and animal intestines. This pathogen is a spore-former, is heat resistant, and does not require oxygen to grow, which is why it can grow in canned foods. The toxin that the spores produce is what causes the symptoms of botulism.  This disease is severe and can be deadly.  The symptoms of botulism are blurred or double vision, difficulty in breathing and swallowing, vomiting, and diarrhea. Onset usually occurs within eighteen to thirty-six hours after ingestion. (3)

So, what can we do to avoid food-borne illness while canning?  Wash your hands and disinfect work surfaces, use the proper canner for the specific foods that are being canned, use the proper jars, lids, and rings, make sure the jars are sealed, store prepared food in a cool, dark place, and observe the food upon opening to ensure that it has not spoiled. Make sure to check out the USDA and FDA websites to obtain current information, instructions, and recipes for your canning needs. While you are enjoying the food you have just preserved, make sure that you stay safe and wash your hands!

1. Canning Tips. https://www.fda.gov/media/107843/download
2. National Center for Home Food Preservation. (n.d.). Retrieved July 19, 2021, from https://nchfp.uga.edu/publications/publications_usda.html
3. Government Relations Team. (2016). FSPCA Preventive Controls for Human Food. CreateSpace Independent Publishing Platform.pg. A4-7.