A Guide to Canning

• If you're using jars from previous canning projects, discard any that have nicks, cracks, uneven rim surfaces, or other defects.
• Wash jars, plus lids and screw bands, in a dishwasher or in hot, soapy water and rinse well (do not towel dry).
• On a jar rack or other metal rack in a large, deep pot, fill jars and pot with water about 2/3 full and bring to a simmer; do not boil. Keep jars hot until you're ready to use them. At the same time, allow lids to simmer in a small saucepan until you're ready to start processing.

• Work in small batches. Place tomatoes in boiling water for 30 to 60 seconds until skins crack (about 3 pounds tomatoes for each quart jar). Immediately plunge into ice water and slip off skin. Remove core; halve, quarter, or leave whole.
• Add 2 tablespoons bottled lemon juice to each jar, then fill with tomatoes and any juices, packing tightly, leaving 1/2 inch of space at the top.
• Remove any air bubbles by sliding a narrow plastic spatula between the jar and food to ensure proper sealing.
• Wipe rim well, then center lid and screw on band just until resistance is met.

• Place jarred tomatoes in pot, keeping them covered with at least 1 inch water. Cover and bring to a boil; boil for 85 minutes, adding water to keep jars covered as necessary.
• Turn off heat and remove pot lid. Wait 5 minutes, then remove jars with a jar lifter (don't tip them) and place upright on a towel on the counter. (Don't worry about wiping water off lids; it's best not to disturb them while the seal is forming.)
• Cool for 24 hours. Check seal (lids should not flex up and down when center is pressed) and wipe jars clean with a damp cloth before storing. Label jars with date.
• New to canning? Equip yourself with classic Ball jars, which have been the home preserver's pick for 125 years. Get helpful information and a starter kit that includes all the basic canning tools for $60 at freshpreserving.com.

Originally published in Ladies' Home Journal, August 2009.