Home Canning Food Preservation Basics
Canning is a form of food preservation that is used primarily to kill micro-organisms, such as the botulinum bacteria which is a toxin causing sometimes fatal food poisoning. While canning can be a fun and enjoyable hobby, and can be rewarding when you save one season's harvest for later in the year, it is also necessary to use the proper techniques and the latest infomation when canning.
Older recipes do not take into proper conseration the dangers of food poisoning, and should not be used. Older techniques, such as sealing a jar with a layer of parrafin wax to be left at room temperature, is no longer considered a safe way to prepare foods. Look for the latest books by year of publication, and contact your local university extension service for the latest and safest methods of canning in food preservation.
Common Equipment Used In Canning
- Jars: Glass jars can be sterilized easily, and can be labeled with large paper labels. The top screw-on lids can be reused (not the rubber gasket parts), so they are economical as well.
Boiling Water Canner:
This type of canner is used on the stove top, and is used for high acid foods. Low acid foods should not be used with this type of canner as the food cannot reach temperatures that will kill the botulinum bacteria. A pot that is made for canning is best purchased instead of using a stock pot already at home since a layer of water needs to be over the top of the jars, as recommended by the latest procedure.
Pressure Cooker Canner:
This type of canner is a pressure cooker, that builds pressure during boiling. This type of canner is the only one safe to use with low acid foods. As the pressure builds, the temperture rises, and the high temperatures can only be reached under pressure. Low acid foods also includs tomatoes now, so canned and stewed tomatoes can no longer be safely canned in a hot water bath.
Funnels and Ladels:
Wide mouth funnels help to trasfer foods from large bowls into the inside of the jars, without spilling on the sides or around the lids. Ladels are especially helpful when liquids are used to avoid splashing.
Spatulas will help remove any air pockets from foods. After thicker foods are placed inside the jars, work the spatula around the jar to remove all air pockets for safe canning.
Canning Racks and Cooling Racks:
Racks are helpful in canning to ensure water is moving all around the jars during processing. Cooling racks are useful to ensure air is cirulating around the jars once the jars have beenn removed from the processing units.
Labels don't have to be fancy or elaborate, and are necessary for indentifying the contents inside the jars. The labels should include what is inside, when it was made, and who made it, if there is ever a question later on of what is inside the jars.
Helpful Guides for Safe Canning
Some of the best sources for safe canning instructions come from colleges and universities and their extension service departments for the public, and from the USDA. Here are some great sites and publications to check out:
The USDA National Center for Home Food Preservation
This has just about everything you need to get started in canning, including complete guides for canning all kinds of fruits and vegetables, and meats and seafoods.
USDA Complete Guide to Canning
This is a PDF printable guide that includes the principles of canning, selecting the foods, and processing the jars.
NC State University Coopertive Extension
This is the guide for home canning of fruits and vegetables in North Carolina.
NDSU Extension Service: Canning Meats
This guide is from the North Dakota State University, and shows how to properly can meats.