Sterilize jars in boiling water for fifteen minutes. Use new lids, and sterilize them according to manufacturer's instructions. The USDA recommends adding two tablespoons lemon juice to each quart of tomatoes to increase the acidity and to help prevent spoilage.
- 18 pounds ripe tomatoes
- 2 tablespoons coarse salt
- 12 fresh basil leaves
Prepare an ice-water bath; set aside. Bring a large stockpot of water to a boil. Score an X in the bottom of each tomato. Boil tomatoes in batches until skins begin to split, 1 to 2 minutes. Transfer to the ice-water bath; let cool slightly. Peel, core, and halve tomatoes. Working over a sieve set in a bowl, remove seeds. Discard seeds, and reserve juice.
Add lemon juice, if using (see note above), 1 teaspoon salt, and 2 basil leaves to each of 6 hot, sterilized 1-quart jars. Fill jars with tomatoes, cut sides down, compressing with a rubber spatula to remove air bubbles. Add reserved juice, leaving 1/2 inch space in each jar's neck. Wipe rims of jars with a clean, damp cloth; cover tightly with sterilized lids and screw tops. Transfer jars, using tongs or jar clamp, to the rack of a large canning pot filled with hot water; cover with water by 2 inches. (Jars should be spaced 1 inch apart, and should not touch sides of pot.) Cover; bring to a boil. Process jars in gently boiling water for 45 minutes. Transfer to a wire rack; let cool 24 hours. Press down on each lid. If lid pops back, it is not sealed; refrigerate unsealed jars immediately, and use within 2 weeks. Sealed jars can be store din a cool, dark place up to 1 year.