Check the individual recipe for the exact amount of space. Fruits with a high juice content and tomatoes can be pre-heated without adding liquid and then packed in the juice that cooks out. Add more hot syrup as needed. Sometimes it is necessary to position and hold down sealing lid while you tighten the band to insure the lid is centered on the top of the jar. Do not over-tighten.
Jars are then ready to be placed on the rack inside hot water canner.
Lower filled rack into canner. Jars should be covered by 1 to 2 inches of water. Add additional boiling water if needed. Cover pot with lid. When the water comes to a rolling boil, start to count the processing time.