Place the strawberries, sugar, and lemon juice in a medium saucepan.
Bring the strawberries to a boil over medium high heat. Reduce heat to medium and simmer to thicken, approximately 15 minutes.
Use a potato masher or fork to mash the berries as much or little as desired.
The jam is done when it is thick and more of a clump when put on a cold spoon or cold plate and tilted. If it runs like honey, it is not thick enough yet and you need to heat it longer.
Store in a jar in the refrigerator for up to three weeks.
Notes
As this jam is not canned or heat treated, it cannot be stored in the pantry.The volume you get will vary with how long you cook it (how thick it is) and how much you mash it.This will roughly fill one pint sized mason jar, which is perfect for storing in the refrigerator.