Fill a large pot with water and bring it to a boil. Add tomatoes (in batches if needed) and allow to boil until skins split. Remove with a slotted spoon and place in a dish. Allow them to cool slightly. Repeat until all tomatoes have been done. Gently peel skins off of the tomatoes and cut off tops. Drain the pot that you boiled the tomatoes in and add skinned tomatoes back to this pot. You can dice, slice or even mash the tomatoes. Bring to a boil over medium-high heat. Reduce heat and stir often, boiling gently for 5 minutes. Add 1 tbsp of lemon juice to each jar. Pour in your tomato mixture, leaving a l/4" headspace. Tap the jars to release any bubbles. Wipe the rim of the jar. Add the lid and ring and secure tightly. Process in a water bath for 35-45 minutes