Water-Bath Canning 101
This is a step-by-step guide to water-bath canning at home. There are a few options to choose from, but all work well. Be sure to set up your jars and workspace beforehand so you can establish a rhythm. Also, be mindful of the processing times given in each recipe.
CLEANING JARS. Wash your jars and lids in hot soapy water and set them to dry completely on a rack or on a clean dish towel.
PREPARING JARS. Glass jars and lids do not need to be sterilized before use if your foodstuffs will be processed more than 10 minutes in a boiling water bath or pressure canner. If jar-processing time is 10 minutes or less, jars must be sterilized before filling. Do this by placing jars in a canning pot, filling with water, and bringing water to simmer. Hold jars in water until ready to use. Conversely, I always hold just-washed jars in a 225-degree oven until ready to use. This is not recommended by the USDA, but I’m still alive to give you the option.
FILLING THE JARS. All canned goods will need headspace to allow for expansion of the food and to create a vacuum in cooling jars. As a general rule, leave . inch of headspace on all jams and jellies and . inch of headspace on all whole fruits. When using whole fruits, release air bubbles in just-filled jars by tapping the jar on the counter or by inserting a wooden chopstick or skewer into the jar and gently stirring the fruit. When placing lids and rings on canning jars, do not overtighten the rings. Secure just until rings have tension and feel snug. Overtightening will not allow air to vent from the jars—a crucial step in canning.
HEATING THE CANNING POT. Fill your canning pot or a deep stockpot half full of water and heat to a low boil. Hold the liquid on a very low boil until ready to use.
FILLING THE CANNING POT. If using a canning pot, place prepared jars of food on the rack in the canner. Do not stack, as you need to allow for circulation of water for proper sealing. Lower jars into the canning pot, and add enough water to cover the jar tops by an inch or more. Cover the pot and return to a boil. Processing times begin once the canning-pot water is brought back up to a boil. This can take as long as 15 minutes, so be sure to keep an eye on your pot and a timer nearby. You may also use a deep stockpot (best only in small-batch preserving) by lining the bottom of the pot with a dish towel and placing jars on top. This helps keep jars from clanging around on the bottom of the pot or tumbling over onto their sides. This form of canning is not universally recommended or endorsed by the USDA. I have seen plenty of farmers and European country folk use this old-school technique, and I’ve adapted their laissez-faire ways.
REMOVING SEALED JARS. Using a jar lifter, or a set of kitchen tongs, remove jars from the canner when the processing time has elapsed. (Remember, processing times begin once the canning-pot water is brought back up to a boil.) Set jars aside on a folded towel to cool. Make sure you do not press on the tops and create an artificial seal.
KNOWING WHEN JARS ARE SEALED. You’ll hear the sound of can tops popping shortly—a sign that a secure seal has been made. Once the jars are cool, check the seal by removing the outer ring and lifting the jar by holding only the lid. If it stays intact, you have successfully canned your food. If the seal is loose or broken, you may reprocess in the water bath within twenty-four hours. (Be sure to replace the lid and check the jar rim for cracks or nicks and replace if necessary.) Conversely, you can refrigerate the jar immediately and use within three weeks.
LABELING AND STORAGE. Once cool, label all jars with date and contents. Successfully sealed jars should be stored in a cool dark place, such as a cupboard. Officially, canned goods keep for up to a year, but I have let them go a bit longer with little effect.
EXCERPTED FROM URBAN PANTRY (SKIPSTONE 2010)