Though it’s somewhat of a rigorous process, home canning has been passed down from generations back. It has given families the opportunity to preserve their own foods for years right from the comfort of their own kitchen. Fruits, vegetables, meats, and poultry can be preserved and savored year-round with this unique way of preserving foods. The great part of canning your foods is the reassurance that you will have of opening your can goods months later and guaranteeing the freshness and quality you come to expect from this process.
Pressure canning is the process one must take in order to can their foods. This blog gives you an overview on do’s and dont’s for the novice canner. You should first understand the acidity and spoilage factors of the food you wish to can. Low-acid foods (vegetables, meat, poultry, and seafood) and high-acid foods (fruits and tomatoes) are both preservable products; however, the USDA only deems low-acid foods safe for canning.
Food spoilage is common if food is left out over time. Microorganisms in the air naturally cause such food spoilage. There are four basic types of agents that act as a catalyst to food spoilage—enzymes, mold, yeast, and bacteria. The canning process naturally interrupts the spoilage cycle of foods. Enzymes, mold, and yeast are destroyed at 212ºF. Bacteria actually thrive on low acids in the absence of air which must be processed at a temperature of 240ºF. This temperature can only be reached with a pressure canner.
Before you start the canning process make sure your pressure canner is thoroughly inspected by the county extension office for proper use. If this is your first canning project, it is recommended to do a test run with water to determine how the canner should function.
Regardless of the canning recipe you are using, make sure it is up to date. No matter how sentimental one might feel about an old canning recipe passed down from their grandmother or great-grandmother, these antiquated recipes usually provide no scientifically-tested processing for safe canning. A more recent recipe usually will.
Make sure you assemble all your ingredients and supplies needed for your canning project. Carefully read the recipe and canning instructions as directed. Never try to substitute or leave out any ingredients.
Mason jars are made of heat-tempered glass for durability and reuse. They are available in standard sizes and will withstand the heat of a pressure canner. Always use these jars. Never use an empty commercial jar of mayonnaise or ketchup for canning. These jars are not made of the same materials and are not designed to preserve foods. The jars should be washed thoroughly in hot water prior to canning. Make sure the jar is thoroughly cleaned before use.
Make sure you use a flat metal lid with a rubber-like seal on the underside. The threaded metal screw band will secure the lid on top of the mason jar. This is called a vacuum cap and can be used repeatedly if kept in good condition. Avoid closures such as zinc caps and glass lids that require a jar rubber. These do not properly determine whether the seal is safe. Avoid commercial one-piece caps if they have a rubber-like gasket because they are intended for one-time use only.
Make sure to determine your headspace for the food being canned. Headspace is the amount of air space between the top of the food or its liquid and the lid. Leaving too much headspace can result in under processing, because it may take too long to release the air for the jar. Leaving too little headspace will also result in inadequate seal. A general rule of thumb is to allow ½ inch of headspace for fruits and tomatoes and 1 inch for all vegetables, meats, poultry, and seafood.
Once the food has been packed in a mason jar, remove air bubbles that are trapped between pieces of food with a clean, nonmetallic spatula. Wipe the sealing surface with a clean, damp cloth to remove any residue. Apply the lid. Once you have used a lid, it’s ideal to buy a canning lid rack in order to wash and sterilize your lids for reuse. For those of you who decide to make several mason jars of preserved foods, a canning rack is ideal for those jars that have just been pressure canned in order to separate them apart in storage and prevent breaking.