Prepare a boiling water bath and 4 regular-mouth 1-pint jars. Prepare the lids according to the manufacturer’s recommendations.

Bring a large pot of water to a boil. While it heats, core the tomatoes and using a small, sharp knife, score the bottom of each tomato with a shallow X. Fill a large bowl two-thirds full with ice-cold water. (The cold water stops the cooking and cools the tomatoes down enough for you to peel them after blanching.)

Working in batches, add the tomatoes to the boiling water and cook for 1 to 2 minutes. Immediately transfer the tomatoes to the bowl of ice-cold water to cool. Repeat with remaining tomatoes, making sure to give the water a chance to come back up to boiling between batches. If the water isn’t hot enough, you will have a hard time removing the skins during peeling.

When the blanched tomatoes are cool enough to handle, grab one and peel the skin off with your fingers. The blanching should have loosened it to the point where it curls off the tomato and is easy to pull free.

Chop the peeled tomatoes and place them in a pot with as much of the juices as you’re able to capture during the chopping process. Bring them to a boil, then reduce the heat and simmer 30-35 minutes, until the juices thicken. Stir regularly to prevent burning.

Add 1 Tbsp of bottled lemon juice to each prepared jar. Ladle the hot chopped tomatoes with their juices into the jars, leaving 1/2 inch/12 mm of headspace. Gently tap the jars on a towel-lined countertop to help loosen any bubbles before using a wooden chopstick to dislodge any remaining bubbles and add additional tomatoes, if necessary.

Wipe the rims, apply the lids and rings, and process in a boiling water bath for 35 minutes.