how full should jars be filled when canning tomatoes?
Place prepared tomatoes in a saucepan and cover with water. Heat to a boil and boil gently for 5 minutes. Add lemon juice or citric acid to canning jars along with 1/2 teaspoon salt to each quart jar, if desired. Pack hot jars with hot prepared tomatoes and fill with boiling water leaving -inch head space.