Canning tomatoes is easier than is seems. Follow the classic recipe at Ball Jar to ensure your food is safe to eat after prolonged storage.
Author Homemade Italian Cooking with Cara
25 - 30lbstomatoes
½tspBall® Citric Acid or 2 Tbsp bottled lemon juice to each hot quart jar or ¼ tsp Ball® Citric Acid or 1 Tbsp bottled lemon juice to each hot pint jar
Salt1 tsp salt to each quart jar or 1/2 tsp salt to each pint jar (if desired)
Ball® Glass preserving jars with lids and bands
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 Ball® Citric Acid or 2 Tbsp bottled lemon juice to each hot quart jar. Add ¼ tsp Ball® Citric Acid or 1 Tbsp bottled lemon juice to each hot pint jar. I used lemon juice.
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.
PROCESS filled jars in a boiling water canner for 35 minutes for pints and 45 minutes for quarts, adjusting for altitude. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.