Canning food is not a new process, although it has regained popularity in the last few years following a rise in interest in organic food. The current canning method was developed in France in the late 1700s and popularized in the USA in the 1850s. The technology surrounding canning products has improved greatly since then, but the basic steps remain the same. While there are two methods of canning--pressurized and water bath--water bath canning is more popular.
There are a few tools you will need for canning. Sets are available as well as individual tools: Jar lifter Glass jars with lids and new bands Canning rack Canning pot, Dutch oven, or stock pot Wide mouth funnel Bubble remover or rubber spatula Canning labels To can food using the water bathing method, you need to start by placing a rack at the bottom of a canning pot, large Dutch oven, or deep stock pot and filling it at least half full with water. Cover the pot with a lid and let the water maintain a simmer. While specialized canning pots are available, a Dutch oven or stock pot will work.
While the water simmers, check over your glass jars, lids, and bands for any cracks, uneven rims, and sharp edges. These imperfections could prevent the jar from sealing properly later in the process and compromise the jar's contents. Once all pieces have been deemed functional, wash everything in hot, soapy water. Pre-heat the glass jars by placing them in the hot water in the pot. Doing so should prevent them from breaking when being filled with hot food later in the process. Keep the lids and bands at room temperature. Although some may still prefer to pre-heat the lids and bands as well, this is not necessary.
Follow the recipe for the food you will be canning. The water bath canning method is ideal for foods with high acids, so best recipes include jams, jellies, pickles, and some salsas. Using a jar lifter, remove the jars from the hot water and fill them one at a time with the prepared food using a wide mouth funnel. Make sure to leave the headspace recommended in the recipe. If needed, remove any air bubbles using a bubble remover or rubber spatula between the inside of the jar and the food to release any trapped air. Do this 2-3 times to ensure all trapped air has been released.
Once the jars are filled, wipe the rim of the jars clean with a damp cloth or paper towel to remove any food residue. Center the lid on the jar before applying the band and adjust until the fit of the band is tight. Place the jar back into the pot of hot water, making sure to cover the jars by 1-2 inches.
Replace the lid on the pot and bring the water to a continuous boil. This begins the processing time. Process the jars according to the time recommended in your recipe. Once done, turn off the heat and remove the lid from the pot. Allow the jars to cool for about 5 minutes before removing them from the pot and set them upright on a towel. Placing them on a towel as opposed to directly on the countertop prevents any breakage due to temperature differences.
Leave the jars alone for 12-24 hours. Do not disturb the bands during this time as it could affect the seal. After 12-24 hours have passed, inspect the lids for seals. There shouldn't be any give when the center of the lid is pressed. Remove the bands and try to take the lids off with your fingertips. If the seal has properly attached, the lids will not move. If the lid does move, the seal did not take and the contents of that jar should be immediately refrigerated. Wipe down the jars with intact seals and label them before storing them in a cool, dry, dark space. The canned food should keep for up to 18 months.