Prepare Jars: Examine all jars for cracks or chips and discard any damaged jars. Wash jars and rings in hot soapy water, rinse thoroughly, and keep jars hot in a 180°F oven or simmering water until ready to fill.
Heat Lids: Place new canning lids in a small saucepan, cover with hot water at 180°F, and keep hot until ready to use. Do not boil lids as this may damage the sealing compound.
Ready Canner: Add 2-3 inches of water to your pressure canner and place the rack inside. Begin heating the canner while preparing the soup to save time during processing.
Cook Vegetables: In a large pot, combine diced carrots, celery, and onions with enough chicken broth to cover vegetables by 1 inch. Bring to a boil and cook for 5 minutes until vegetables are slightly tender but still firm.
Add Chicken: Add cooked chicken pieces to the vegetable mixture and add enough hot chicken broth to cover all ingredients by 1 inch. Bring mixture to a boil and maintain heat throughout filling process.
Fill Jars: Using a ladle and wide-mouth funnel, fill hot jars with soup mixture, distributing solids evenly among jars. Leave exactly 1 inch headspace from the rim of each jar.
Season and Cover: Add salt and pepper to each jar if desired, then cover contents with hot broth, maintaining the 1 inch headspace. Remove air bubbles by running a plastic tool around the inside of each jar, adjusting liquid level as needed.
Clean and Seal: Wipe jar rims thoroughly with a clean, damp cloth to remove any food particles or grease that could prevent proper sealing. Center hot lids on jars and apply rings finger-tight only.
Load Canner: Place filled jars on the canner rack using a jar lifter, ensuring jars do not touch each other. Lock canner lid in place and heat on high until steam vents steadily for 10 minutes to purge air from canner.
Process Under Pressure: Place pressure regulator on vent and process at 11 pounds pressure for 100 minutes for quarts or 75 minutes for pints. Adjust pressure for altitude: 1,001-2,000 feet use 11 lbs, 2,001-4,000 feet use 12 lbs, 4,001-6,000 feet use 13 lbs, 6,001-8,000 feet use 14 lbs. After processing, turn off heat and let pressure return to zero naturally before opening canner.
