Canning Food at Home
Some people jar food for health reasons. Others do it because their garden was bountiful. Either way, "home canning really allows you to select the freshest, ripest, most nutritionally dense raw materials," says Ashley English, author of Homemade Living: Canning & Preserving With Ashley English: All You Need to Know to Make Jams, Jellies, Pickles, Chutneys & More. Canning is easy to learn and involves surprisingly little in the way of supplies, says Marisa McClellan, a canning instructor in Philadelphia and author of the blog FoodInJars.com. "If you have a well-equipped kitchen, you can start canning right away," she says. To get going, follow the steps below.
1. Choose a method. There are two ways to can: by boiling jars in a bath of water or by using a pressure canner. Since pressure canning requires more skill (and purchasing a canner), the following steps are for water-bath canning alone.
2. Gather your supplies. You can go overboard with canning supplies—canning pot, jar lifter, canning rack, air bubble remover, and so on—which are available at some grocery and hardware stores as well as online. But McClellan says there are only a few things you absolutely need: a pot to boil the jars in (a stockpot works well) and canning jars with screw bands and lids (the U.S. Department of Agriculture only approves use of widemouthed glass mason jars with two-piece, self-sealing lids). You can use a chopstick to push out bubbles and tongs with rubber bands wrapped around the ends for traction as a jar lifter.
3. Get the right recipe. The steps for creating strawberry jam aren't the same as for pickling and canning green beans. A good recipe will list ingredients, cooking times, and how long to process the canned food in its boiling water bath. From there, play around with ingredients, like low-sugar pectin. "You control the salt, sugar, and all other ingredient selection, enabling you to customize according to dietary needs or preferences," says English.
4. Sterilize your jars. While you prep your food, sterilize the jars in a pot of boiling water for 10 minutes. "Doing so kills off any microorganisms that might be present," says English. When you remove the jars from the boiling water, keep them on a towel-lined countertop until you're ready to fill them.
5. Add acid. When the pH of your food is too low, you risk food-borne illnesses like botulism. "This is perhaps the most important safety concern with home canning," says English. To stay safe, recipes will use an acid to create the briny liquid that will cover canned vegetables. (Most fruits are already acidic enough, though some will use citrus for flavor.) For example, you might use vinegar-based brine to can cucumbers.
6. Fill the jars. As soon as your jam is prepared, pour it into a jar (a funnel helps), leaving as much room between the contents and the top of the jar (what's called "headspace") as your recipe calls for. The same goes for vegetables: Place veggies in a jar, then pour in the brine, minding the headspace. Before you put the lid on, clean around the rim. "Sometimes, an almost imperceptible amount of food debris is left on the rim," says English. "It can interfere with the lid's ability to seal properly."
7. Release bubbles. Once your vegetables and brine are in a jar, poke around with a chopstick or spatula to force out all of the air bubbles. Skip this step, and you might not get a good seal.
8. Process the jars. After your jars have been filled and their tops are securely in place, you need to boil them in water. Boiling time depends on what you're making, and will probably be specified in your recipe as "processing time." The step is crucial because it keeps your preserved food safe. There are three ways to know that your jars have properly sealed: The bubble on the top of the lid will become flat, you'll hear a popping sound as the seal is formed, and if you pick up the jar by the lid, it will feel secure. If you find a bulging lid, discard the jar and its contents.
9. Store your food. When the jars have cooled to room temperature, store them in a dark, cool place until you're ready to use them. They'll last about a year. Dating the jars by using a marker or label can help you keep track of the food's use-by date.