1. Wash your canning jars, lids, and screw bands in hot soapy water and rinse well.
2. Sterilize the canning jars by submerging them in boiling water for 10 minutes.
3. Make your tomato paste by removing the cores, seeds, and stems from the tomatoes and cooking diced tomatoes for an hour until the volume reduces by half.
4. Run the tomatoes through a food mill, then add them to a stockpot.
5. Add canning salt, garlic cloves, bay leaves, and citric acid or bottled lemon juice, and bring the mixture to a boil. Stir constantly until the mixture reduces again by half and forms a thick paste.
6. Remove the garlic cloves and bay leaves and discard.
7. Ladle the hot tomato paste into hot half-pint canning jars, leaving 1/2-inch headspace.
8. Remove excess air bubbles using an air bubble remover tool from each jar.
9. Wipe the rims of the jars with a clean paper towel or damp kitchen cloth.
10. Cover with clean lids and apply the screw bands, tightening until fingertip tight.
11. Prepare a boiling water canner by filling it halfway with boiling water. Add the jar rack into the canner and load the jars of tomato paste onto the rack.
12. Ensure boiling water covers the jars by at least 1 inch.
13. Bring the water to a rolling boil, then cover the canner with a lid.
14. Process the jars in the hot water bath for 45-60 minutes per your elevation:

• 0 -1000ft (45 minutes)
• 1,001 – 3,000ft (50 minutes)
• 3,001 – 6,000ft (55 minutes)
• 6,001ft and up (60 minutes)

Post Processing

1. When processing is complete, remove the jars from the hot water using canning tongs or a jar lifter and place them on a clean towel-covered countertop, placing them 1 inch apart. Don’t put the jars on a cold surface, as they can easily break.
2. Let the jars sit undisturbed at room temperature for 12-24 hours.
3. Remove the screw bands from the jars. Check that the jars are properly sealed and the lids don’t flex up and down.
4. Label and date sealed jars and store them in a cool, dry place. For any unsealed jars, reprocess or refrigerate and use the contents within 1 week.