Prepare boiling water canner. Heat jars in simmering water until ready for use. Do not boil. Wash lids in warm soapy water and set bands aside.

Wash tomatoes. Dip in boiling water 30 to 60 seconds. Immediately dip in cold water. Slip off skins. Trim away any green areas and cut out core. Leave tomatoes whole or cut into halves or quarters.

Cut tomatoes into quarters to measure about 2 cups. Transfer to a large stainless steel saucepan and bring to a boil over medium-high heat. Using a potato masher, crush tomatoes to release juices. While maintaining a gentle boil and stirring to prevent scorching, quarter additional tomatoes and add to the saucepan as you work. The remaining tomatoes do not need to be crushed, as they will soften with heating and stirring. Continue until all tomatoes are added, then boil gently for 5 minutes.

Add ½ tsp citric acid or 2 Tbsp bottled lemon juice to each hot quart jar. Add ¼ tsp citric acid or 1 Tbsp bottled lemon juice to each hot pint jar.

Pack hot tomatoes into hot jars to within a generous 1/2 inch of top of jar. Press tomatoes into the jar until the spaces between them fill with juice, leaving 1/2 inch headspace. Add 1 teaspoon salt to each quart jar, 1/2 teaspoon to each pint jar, if desired. Remove air bubbles and adjust headspace, if necessary, by adding hot tomatoes. Wipe rim. Center hot lid on jar. Apply band and adjust until fit is fingertip tight .Place jar in boiling-water canner. Repeat until all jars are filled.

Water must cover jars by 1 inch. Adjust heat to medium-high, cover canner, and bring water to a rolling boil. Process pint jars 35 minutes and quart jars 45 minutes, adjusting for altitude. Turn off heat and remove cover. Let jars cool 5 minutes. Remove jars from canner; do not retighten bands if loose. Cool 12-24 hours. Check lids for seal, they should not flex when center is pressed