There’s nothing better than using home-canned tomatoes in an Italian recipe or pulling out a quart of fresh-frozen peaches to make a bubbly cobbler. However, if the only thing you know about food preservation is from your grandmother’s jam-making on hot summer afternoons, you have a whole lot of catching up to do.
“People have been preserving food for centuries, but as we learn more about foodborne illness and spoilage—and changes in our food supply and developments in canning equipment take place—recommendations are updated frequently to provide reliable ways to safely reap the bounty of our garden’s harvest,” says food safety specialist Elizabeth Andress. “Food preservation knowledge and techniques need to be based on sound food science for safety. We’re still targeting the same bacteria in canning as we have for a long, long time.”
From the garden to the table, food handling and kitchen hygiene standards are crucial to successful food preservation, says Elizabeth, who is director of the National Center for Home Food Preservation with Georgia Cooperative Extension.
She encourages consumers to rely on recent information rather than tradition.
Start With Some Canning Basics
Different equipment is needed for each of three canning methods: pressure canning, water-bath canning and steam canning.
“Each has its benefits and drawbacks, but in any case, it’s important to follow the instructions exactly and familiarize yourself with each before attempting to can at home,” Elizabeth says. “An important consideration for choosing the proper canning technique depends on the acidity of the food you’re canning. For instance, higher-acid foods like fruits can be processed in a water-bath canner. But foods with a lower-acid content—such as meats and soups—must be preserved using a pressure canner.”
Foods such as tomatoes can be preserved using a water bath, but it’s important to add citric acid or lemon juice to acidify them. Because of the added vinegar, pickles can be canned using a water bath if a tested recipe is followed.
“For a beginner, we suggest canning peaches or making applesauce to become comfortable with the equipment and the process,” Elizabeth says. “Both use the water-bath method, which involves placing filled containers into a large pot of boiling water that covers the whole jar and lid, and boiling them for the exact time shown in the recipe. Whenever canning, we recommend using a tested recipe from a reliable source, such as the National Center for Food Preservation.”
Peaches can be peeled, cut into halves or slices, packed into jars, then covered with water or sugar syrup before putting on the lids and placing the jars in boiling water.
“Choose between raw pack or hot pack when you fill the jars,” Elizabeth says. “With the raw pack, put the freshly peeled and sliced peaches into a clean hot jar, then cover with hot syrup. Hot-pack canning means that you cook the peaches in syrup first, then fill the jars with the hot fruit and liquid before processing.”
Applesauce can be processed using a water bath as well. Use the hot-pack method for filling the jars.
“When putting on the lids, be sure to wipe the jars’ sealing edges with a clean, damp cloth to remove bits of food that may prevent the jars from sealing properly,” Elizabeth adds.
Consider Freezing Some Items
Certain foods freeze better than others.
“Many vegetables are not suited for freezing, such as cucumbers, radishes, raw potatoes or onions,” Elizabeth says. “On the other hand, vegetables like green beans and asparagus, and fruits like blueberries or peaches, are easy to freeze.”
Green beans, corn, carrots and broccoli need to be blanched—submerged in boiling water for the prescribed time on the recipe—before freezing. Transfer them to an ice bath for rapid cooling.
“Once they’re blanched and drained, place them in a single layer on a cookie sheet and freeze them individually,” Elizabeth says. “Then pack into freezer-safe containers, label and store.”
Blueberries, cherries, grapes, fresh sliced peaches and strawberries can be placed on cookie sheets and frozen individually before packing. Remove as much air as possible before sealing.
“Fruits can be frozen with or without added sugar or liquid, depending on what you plan to use them for,” Elizabeth says. “Freezing can be an easy way to preserve food. However, the same safe-handling guidelines apply. Keep your work surfaces clean, wash your hands often, and carefully label the packages with the date processed and the contents.”
Herbs can be frozen, too.
“If you grow basil or oregano in the summer, just chop the fresh leaves and put them into ice-cube trays covered with water,” Elizabeth says. “Once they’re frozen, package them in a freezer-safe container. When you need some herbs for soup or a sauce recipe, take out the frozen cube and add it to the sauce. You can also do this for smaller quantities of hot peppers or onions.”
Getting Back to Kitchen Basics
Today’s conveniences have made it easier to enjoy the rewards of growing your own food long after the harvest is over.
“Because of the pandemic, more and more people are turning to home food growing and preservation,” Elizabeth says. “Just be certain to follow all the guidelines and recipes exactly. Don’t take any shortcuts or change ingredients or timing.
“The recipes we provide through the National Center for Preservation have been extensively tested. The key is to be meticulous, whether you’re canning or freezing. That way you can be assured of the freshest flavors and the safest results.”
Practice Good Kitchen Hygiene When Processing and Preserving Food
- Label and date your home-processed foods.
- If a lid does not properly seal when canning, refrigerate the contents and consume them within seven days. You can reprocess within 24 hours if the food was processed correctly but the lids did not seal, using new lids and jars. If the food was underprocessed—whether the lids have sealed or not—reprocess within four hours.
- Use new flat lids when canning. It is not necessary to use new rings.
- Choose containers specifically designed for preserving food, such as Ball glass jars for canning and freezer-weight plastic bags and boxes.
- Process foods exactly as described in recipes. Do not reduce times.
- Canned foods may be stored for up to 12 months in a cool, dark place, such as a pantry or closet. If processed correctly, they may be stored longer, but they may lose quality and nutritional value. Frozen fruits and vegetables may be stored at 0 degrees F for eight to 12 months.
- Do not use chipped or cracked glass containers to preserve foods.
- Beware of conditions that create botulism, including underprocessed foods, containers with bulging lids, contents with discoloration on the top when opened or bad smells. Discard these foods.