Cut an X into the bottom of each tomato, which will make peeling easier. Boil a large stockpot or lobster pot of water and add all tomatoes, working in batches if necessary. When their skins begin to retract after a minute or so, remove the tomatoes from the water and plunge into cold water to stop the cooking and loosen the skins.
Peel the tomato skins off, and cut out the stems. Press the peeled and cored tomatoes firmly into the sterilized jars until there is only 1/2-inch remaining at the top.
Once the jars are filled, add a teaspoon of Kosher salt and a tablespoon of bottled lemon juice to each quart. Place the lids and rims on the jars, and tighten.
Prepare a large boiling water bath in a stockpot or lobster pot, making sure the water is deep enough to completely cover the jars. Once the water has come to a boil, arrange the jars on a wire jar rack, and lower into water. Allow the jars to process in the water bath for 45 minutes.
When the processing is complete, carefully remove the rack and place on a heatproof surface. Cover the jars with a clean dishtowel, and allow them to cool at room temperature for a few hours.
Test the seals to ensure proper processing, label the jars with the date, and store in a cool, dark place (like a pantry) to enjoy for up to a year.