Add all ingredients to a large boiling pot.
Bring mixture to a boil on medium-high heat. Once boiling reduce the heat to medium-low and simmer for 15 minutes, stirring continuously using a potato masher to prevent the jam from burning on.
After 15 minutes, remove from heat, mash with a potato masher, and let stand for 20 minutes (the jam will thicken as it sits and cool a little for safer handling).
Wash and prepare one large mason jar.
Preheat the oven to 250F and place the glass jar, not the lid, in the oven for 10 minutes to heat up. Remove the jar from the oven carefully using an oven safe glove with agood grip.
Carefully, using a heat safe mitt, fill the hot jar to almost full and place the lid on tightly.
After about an hour you will hear a popping noise, that is the lid sealing to the jar.
Let the jarred jam sit for 4-5 hours or overnight to allow bottles to self-seal, and cool to room temperature before refrigerating.