Prepare the Tomatoes

1. Wash the tomatoes thoroughly under cool running water.
2. Working in batches, place the tomatoes in boiling water for 30 to 60 seconds, or until the skins begin to split.
3. Immediately transfer the tomatoes to a large bowl of ice water.
4. Slip off the skins, remove the cores and cut the tomatoes into quarters.
5. Place the prepared tomatoes in a large stockpot. Bring them to a boil and cook uncovered for 20 minutes.
6. Pass the cooked tomatoes through a food mill or sieve to remove the seeds and create a smooth tomato pulp.

Prepare the Marinara Sauce

7. Heat the vegetable oil in a large skillet over medium heat.
8. Add the measured onion, garlic, celery or green pepper and optional mushrooms. Sauté until the vegetables are tender.
9. Combine the sautéed vegetables and prepared tomato pulp in a large stockpot.
10. Add the salt, black pepper, oregano, parsley and brown sugar.
11. Bring the mixture to a boil. Reduce the heat and simmer uncovered until the sauce reaches serving consistency and its volume has been reduced by nearly one-half.
12. Stir frequently while the sauce reduces to prevent scorching.

Prepare the Pressure Canner

13. Prepare the pressure canner according to the manufacturer’s directions.
14. Wash the jars, lids and screw bands in hot, soapy water. Rinse thoroughly and keep the jars hot until ready to fill.
15. Keep the marinara boiling hot while filling the jars.

Fill the Jars

16. Ladle the hot marinara into hot pint or quart jars, leaving 1 inch of headspace.
17. Run a bubble-removal tool around the inside of each jar. Adjust the headspace if necessary.
18. Wipe the jar rims with a clean, damp cloth.
19. Center the lids on the jars and apply the screw bands until fingertip-tight.
20. Place the filled jars in the prepared pressure canner.

Process the Marinara

21. Vent and operate the pressure canner according to the manufacturer’s instructions.
22. Process pint jars for 20 minutes or quart jars for 25 minutes at the correct pressure for your canner and elevation.
23. If the pressure drops below the required level during processing, return the canner to the correct pressure and restart the entire processing time.
24. When the processing time is complete, turn off the heat and allow the canner to depressurize naturally. Do not force-cool the canner.
25. Open the canner according to the manufacturer’s directions, tilting the lid away from your face.
26. Transfer the jars upright to a towel-lined counter. Allow them to cool undisturbed for 12 to 24 hours.
27. Remove the screw bands and check the seals. Refrigerate and promptly use any jars that did not seal.
28. Label the sealed jars and store them without the screw bands in a cool, dry, dark location.

Pressure Settings

Dial-Gauge Pressure Canner

• 0 to 2,000 feet: 11 pounds
• 2,001 to 4,000 feet: 12 pounds
• 4,001 to 6,000 feet: 13 pounds
• 6,001 to 8,000 feet: 14 pounds
• Above 8,000 feet: 15 pounds

Weighted-Gauge Pressure Canner

• 0 to 1,000 feet: 10 pounds
• Above 1,000 feet: 15 pounds