Bring a large pot of water to a boil. Add peaches a few at a time for 30-45 seconds, and then immediately take them out and put them in a bowl of ice water. This should make the skin super easy to remove.
After peeling all the peaches, quarter them and remove the pits. Place all of them in a large pot and pour the lemon juice over them, followed by the sugar. Toss to make sure all the peaches are evenly coated.
Let the peaches sit at room temp until all the sugar has dissolved, about 30 min - 1 hour.
Bring the pot to a light boil, and then simmer for 10 minutes, stirring occasionally. Turn off the heat and allow the peaches to cool.
Once cool, repeat step 4 another 4 times, for a total of 5. If you'd like thicker jam, try a 6th time. Be very careful not to burn the jam, especially during the last few times - it'll become easier and easier to burn if you're not paying attention!
Once cooled, ladle into jars of your choice. The jam will keep in the fridge for a few months. If you want shelf stable jam like you'd get in the store, you can follow canning procedures for any other jam. I chose not to do this because I knew I'd get through all the jam plenty quick.
Enjoy!
