By this time of year, many gardeners are seeing the fruits (or vegetables) of their early spring labor. Local farmers markets are ripe with local produce, which may cause us to purchase more than we can possibly eat before it goes bad.
So, what is the answer to this overabundance of produce? Canning.
You can make your favorite tomatoes into a tomato sauce to use throughout the season while preserving that fresh garden taste. Or what about those sweet Georgia peaches? Why not try a peach salsa recipe to enjoy throughout the year.
Now that the decision has been made to preserve those foods, how do we know that we are preserving foods safely?
First, it starts with understanding the goal of preserving foods. Not only do we want to maintain the quality, we also want to make perishable foods shelf-stable for up to one year. Oxygen and enzymes are present throughout fresh food tissues, which causes food to spoil.
Heating foods in a sealed canning jar to a specific temperature for a specific length of time destroys normal levels of heat-resistant microorganisms that can spoil foods, appetites and even lead to a trip to the hospital.
Air is also forced from the jar during processing, creating a vacuum seal. This prevents bacteria from entering the jar, contaminating the food.
Collectively, these practices remove oxygen, destroy enzymes, prevent the growth of undesirable bacteria, yeasts, and molds, and help form a strong vacuum in jars.
Next, we need to understand the foods we are preserving. For canning purposes, foods can be divided into two categories: low-acid and high-acid.
Foods that are considered high-acid have a pH of 4.6 or lower and have naturally high levels of acid. These are fruits and soft spreads. Pickles, sauerkraut, and tomatoes also fall under this category due to the addition of acid, such as vinegar. If the recipe calls for added acid, be sure to use commercially bottled lemon juice, 5% acidity vinegar or citric acid. These low-acid foods should be processed in a boiling water canner.
Low-acid foods have a pH higher than 4.6 and include vegetables, soups, meat, meat sauces, poultry, and seafood. These foods can only be processed in a pressure canner using a USDA-tested method, which can be found at nchfp.uga.edu.
Temperatures in a pressure canner must be higher than the boiling point to destroy a heat-resistant spore, such as botulism.
If you’ve purchased a dial gauge pressure canner or inherited one from family, it’s important to have the dial gauge tested for accuracy. An inaccurate gauge could measure pressure lower or higher than actual pressure.
Most UGA Extension offices provide free dial gauge testing. Contact the Hall County Extension office at 770-535-8293 or email at email@example.com.
Carin Booth is the family and consumer sciences agent at the University of Georgia Cooperative Extension Office in Hall County.