Prepare boiling water canner. Heat jars in simmering water until ready to use, but do not boil. Wash lids in warm soapy water and set aside with bands.
Wash tomatoes under cold running water. Peel by blanching for 30-60 seconds in boiling water, and immediately transferring to a large bowl of ice water. Slip off the peels and core the tomatoes.
Add ¼ teaspoon citric acid or 1 tablespoon bottled lemon juice to a hot pint jar; ½ teaspoon citric acid or 2 tablespoons bottled lemon juice to a hot quart jar. If using salt, add ½ teaspoon salt to pint jars, or 1 teaspoon salt to quart jars.
Pack raw tomatoes into jar, pressing gently so that tomato juice fills the spaces between tomatoes, leaving ½-inch headspace.
Remove air bubbles and adjust the headspace as needed. Clean jar rim, and then center lid on jar and adjust band to fingertip-tight.
Place jar on a canning rack in the boiling-water canner. Repeat until all jars are filled.
Lower the rack into the canner, making sure that the water rises at least one inch above the lids of the jars. Cover and bring to a rolling boil. Process both pint and quart jars for 1 hour and 25 minutes (85 minutes).
Turn off heat and remove lid. Let jars cool for five minutes, then remove jars to a folded dish towel. Cool 12 hours and test seals. Label and store jars.