Step 1

Prepare boiling water canner. Heat jars in simmering water until ready for use. Do not boil.  Wash lids in warm soapy water and set bands aside.

Step 2

Combine 1 cup of tomato purée, onion, celery, carrot and garlic in a large stainless steel saucepan. Bring to a boil over medium-high heat, stirring frequently. Reduce heat, cover and boil gently until vegetables are tender, about 5 minutes. While maintaining a steady boil, add remaining tomato purée, 1 cup at a time, stirring frequently. Stir in lemon juice, salt, black pepper and hot pepper flakes. Increase heat to high and bring to a full rolling boil; boil hard, stirring frequently, until mixture is reduced by one third, about 15 minutes.

Step 3

Ladle hot sauce into hot jars leaving 1/2 inch headspace. Remove air bubbles and re-measure headspace. If needed, add more sauce to meet recommended headspace. Wipe rim. Center lid on jar. Apply band and adjust until fit is fingertip tight.

Step 4

Process filled jars in a boiling water canner for 35 minutes, adjusting for altitude. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.