Remove the skins from the persimmons and cut into small pieces. Make sure to remove the stems and seeds.
Add sliced persimmons to a sauce pan with lemon juice. Heat over medium heat for 15 minutes to soften up the fruit. Use a potato masher to help the process along.
After 15 minutes, add sugar and salt and stir until the sugar melts. Simmer for another 10-15 minutes to thicken up the jam. Use the potato masher to crush the fruit if it still seems too lumpy.
Test the jam by spooning a small amount onto a plate. Tilt the plate, and if it doesn’t slide, the jam should be done. Cook for a few more minutes if it fails the test.
Remove the sauce pan from the heat. You can stop here if you want, but I wanted a smoother consistency, so I used an immersion blender to smooth out the jam.
Spoon jam into a jar for storage. You can store the jam for up to a year in your pantry if unopened. Once opened, they last up to a month in the fridge.