Rinse your blueberries.
Add blueberries, sugar, and lemon juice to a pan and cook on medium heat until it begins to boil, stirring frequently.
Reduce the heat to medium-low and cook for about 20 minutes. While it simmers, smash some of the blueberries with the back of a spoon.
After 20 minutes, your jam should reach 220℉ (use a candy thermometer to test).
For another test, or if you don't have a candy thermometer - set a plate in the freezer for about one minute.
Drop a quarter-sized amount of the hot preserves onto the plate and put back in the freezer for another minute.
If you can run your finger through and it wrinkles up (aka, the preserves don't quickly fill the path you made with your finger), your preserves are ready!
Add the hot blueberry preserves to a mason jar and let cool completely.
Once the preserves are cooled, seal, and store in the fridge.
Serve on biscuits, toast, pancakes, or anything else you can think of. Enjoy!