Step 1

Combine the blueberries (or strawberries) and the sugar in a medium saucepan. Mash berries slightly with a potato masher or the bottom of a fork. Bring mixture to a boil over medium-high heat, stirring occasionally.

Step 2

As soon as the berries begin to boil, begin to stir.

Step 3

Continue to cook and stir occasionally until jam begins to thicken. During the last few minutes of cook time, stir vigorously so that the mixture doesn't stick to the bottom of the pan.When the mixture reaches a gel consistency, remove pan from the heat.

Step 4

Pour into a clean glass jar.