Directions

1. 1

   Core and roughly chop all the tomatoes into large pieces.

2. 2

   Heat the olive oil in a large, heavy-bottomed pot over medium heat. Add the chopped onion and garlic along with the salt. Sauté, stirring occasionally, until the onion becomes transparent and softened, about 10 minutes.

3. 3

   Add all the chopped tomatoes to the pot and increase heat to bring the mixture to a boil. Once boiling, reduce heat to a gentle simmer and cook for 20 to 30 minutes, stirring occasionally, until the tomatoes have completely broken down and become soft.

4. 4

   Set a food mill or fine sieve over a large, clean bowl. Working in batches, carefully press the hot tomato mixture through the mill or sieve, using a wooden spoon to force the pulp through while allowing skins and seeds to remain behind. Discard the skins and seeds. This step removes the bitter skins and seeds for a refined texture.

5. 5

   Return the strained tomato sauce to the pot and simmer over medium-low heat, uncovered, stirring occasionally to prevent sticking. Allow the sauce to reduce by one-third to one-half in volume, which concentrates the flavor. Cooking time varies depending on tomato juiciness—plan for 2 to 4 hours. About 30 minutes before the sauce reaches desired thickness, stir in the chopped basil and parsley.

6. 6

   While the sauce simmers during its final 30 minutes, prepare your canning equipment. Fill a large water bath canner with water and bring to a rolling boil. Submerge 4 quart-sized canning jars in the boiling water for 10 minutes to sterilize them.

7. 7

   Place the lids in a small saucepan and cover with water. Heat over very low heat, maintaining a gentle simmer (not a rolling boil) to keep the lids warm and flexible for proper sealing.

8. 8

   Once the sauce reaches the desired consistency, carefully remove the hot sterilized jars from the boiling water using a jar lifter, pouring the water back into the canning pot. Add 3 tablespoons of bottled lemon juice to the bottom of each empty jar. Using a large ladle, carefully pour the hot sauce into each jar, leaving exactly ½ inch of headspace between the top of the sauce and the rim of the jar.

9. 9

   Wipe the rims of each jar thoroughly with a clean, damp kitchen towel to remove any sauce residue. Remove a lid from the simmering water, place it on the jar, and screw the ring on fingertip-tight—do not overtighten. Repeat for all jars.

10. 10

    Place the filled jars into the boiling water bath, ensuring they are completely covered with at least 1 inch of water. Cover the canner and maintain a rolling boil. Process for 40 minutes.

11. 11

    Once processing time is complete, carefully remove the jars from the boiling water using a jar lifter and place them on a clean towel or wire rack at room temperature. Do not adjust the lids. Allow the jars to cool undisturbed for 24 hours at room temperature.

12. 12

    After 24 hours, check each jar for a proper seal by pressing the center of each lid—a sealed lid should not flex or pop. If sealed, remove the rings, wipe the jars clean, and store in a cool, dark place for up to 1 year. If any lid has not sealed (it flexes or makes a popping sound), remove the ring, refrigerate that jar immediately, and use the sauce within 1 week.