Place a small plate in the freezer. This will help us know when the jam is ready. It just has to be chilled prior to testing the jam on it.
In a medium saucepan, add in the blueberries and sugar. Place over medium heat.
Using the back of a wooden spoon or a potato masher, mash the blueberries to help get the juices flowing. Stir occasionally.
Let cook for about 18 - 20 minutes. Once it becomes thick and syrupy, remove your plate from the freezer. Place the jam on the plate and if the edges set up after sitting on the plate about 1 minute, it's ready. Mine only took 18 minutes to cook.
Remove from the heat and place in a container. Place in the refrigerator. It will set up when it's chilled.