Home Canning Basics for High Acid Foods

You should always carefully inspect your canning jars for nicks, cracks, uneven rims or sharp edges. I personally use Ball brand canning jars, because of their superior reliability, uniformity, and affordable price, but there are many brands of equal quality on the market. Any abnormality in the canning jar can cause the seals to leak or even cause the jar to break during the canning process. Check the metal bands for proper fit, although most are uniform, you may occasionally find a jar that your bands just don't seem to fit. Examine each of the lids to ensure they are not scratched and the sealing compound is even and complete. You may re-use canning jars and bands, however - never reuse a lid! Wash jars, lids and bands in hot, soapy water; rinse, and allow to dry.

To sterilize your canning jars, place canning jars in a large stockpot. Cover jars with water and place over high heat. Bring water to a simmer (180° F); reduce heat and keep jars in hot water until ready to use. If you have a dishwasher that reaches this temperature in the washing cycle, you may use the dishwasher to sterilize the canning jars, leaving them in the heated dishwasher until you're ready to use them.

I recommend you prepare your food according to it's recipe specifications and allow it time to cool to a temperature that wouldn't cause burn or injury when pouring the food into your canning jars. There's always the potential for splash back, even if you use a ladle to scoop the food into the canning jars. Follow guidelines for recipe preparation, jar size, canning method and processing time. To sterilize the lids, place them in a small saucepan. Cover lids with water. Bring to a simmer (180° F); keep lids hot until ready to use. Do not allow the water to reach a boil! This ruins the sealing compound on the lids. Although it is not necessary, if you wish to sterilize the bands, you may do the same to them in a saucepan.

Fill hot jars one at a time with prepared food. Do not use an assembly line method for filling jars! Complete one jar at a time, and make sure to leave "headroom" from the brim (just below the grooved rim where the band attaches) of the canning jar to the food the jar contains. Over-filling and under-filling can result in seal failure. Headspace is determined by the food type:
Jams, jellies and other fruit spreads - ¼ inch
Fruits and tomatoes - ½ inch
Fruit juices - ¼ inch
Pickles, relishes and chutneys - ¼ inch
Sauces, vinegars and condiments - ¼ inch

Remove air bubbles by sliding a plastic spatula or wooden spoon between jar and food; press gently on the food to release trapped air. Never pound jar on cabinet to release bubbles, this could result in a chipped or cracked canning jar! Repeat around circumference of jar. After you've removed the air bubbles, you may need to readjust the fill level.

Wipe rim and threads of jar with a clean, damp cloth to remove any food residue. Center the lid on jar with the sealing compound side on the jar's rim. Apply band, screwing down evenly and firmly - just until fingertip tight. "Fingertip tight" is as snug as the band can be applied with your fingertips. This allows the lid to vent air during processing. The lid must exhaust the air in order to form a vacuum seal.

Place jar on rack in canner. Repeat these steps for each canning jar, one jar at a time. When all jars are filled or canner is full, lower rack into the water. Be sure water covers jars by at least 1 inch; add boiling water if required. Place lid on canner and turn heat to medium high.

When the water reaches a full rolling boil, begin counting processing time. At altitudes up to 1,000 feet above sea level, follow recipe processing time. At altitudes higher than 1,000 feet above sea level, increase processing time as recommended for your elevation.

When time has elapsed, turn off heat and remove canner lid. Allow boil to subside, then lift jars without tilting and place them upright on a towel to cool in a draft-free place. Do not tighten bands that seem loose or test for a seal while the canning jars are still hot!

Cool jars undisturbed for 24 hours.

After jars have cooled, check lids for seal by pressing on the center of the lid. If the lid is pulled down and does not flex up or down when pressed, remove the band and slightly lift the jar by the lid. Lids that do not flex and cannot easily be removed with your fingertips have a good seal. An unsealed jar in unsafe and will spoil rapidly. Always refrigerate or reprocess the food from any unsealed jars!

You may now remove the bands, and save them for later use. Wipe jars and lids with a clean, damp cloth and allow jars to air dry. You can now label them with the contents and the year and month, and store jars in a cool, dry, dark place. For best quality, use home canned foods within one year. I also recommend that you check your canned jar's seals once every 3 months, just to make sure a seal hasn't came loose. And of course, discard any food from a stored canning jar in which the seal has became loose!