Canned Tomato Soup

Step 1
Place tomatoes, celery, and onions into a large pot. Pour in just enough water to cover vegetables; bring to a boil. Reduce heat and simmer until tomatoes are tender, 20 to 30 minutes. Pour through a strainer or food mill, discard solids, and return liquid to the pot; stir in sugar and salt.

Step 2
Blend together butter and flour in a blender until smooth and creamy; pour in tomato juice. Blend until smooth, then pour into liquid in the pot. Cook and stir over medium heat just until tomato soup is hot.

Step 3
Sterilize the jars and lids in boiling water for at least 5 minutes. Pack tomato soup into the hot, sterilized jars, filling to within 1/4 inch of the top. Run a knife or thin spatula around the insides of the jars to remove any air bubbles. Wipe the rims with a moist paper towel to remove any residue. Top with the lids and screw the rings on tightly.

Step 4
Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower the jars 2 inches apart into boiling water using a holder. Pour in more boiling water to cover the jars by at least 1 inch. Bring water to a rolling boil, cover the pot, and process for 20 to 30 minutes.

Step 5
Remove the jars from the stockpot and place onto a cloth-covered or wood surface, several inches apart, until cool. Press the center of each lid with a finger to ensure the lid does not move up or down. Store in a cool, dark area. Wait at least 12 hours before opening.