Begin by gathering your ingredients: fresh or frozen blueberries, lemon zest, lemon juice, and maple syrup. Rinse one cup of blueberries under cold water, and check for ripeness. Zest and juice one small lemon.

In a quart-sized saucepan over medium heat, combine the prepared blueberries, lemon zest, lemon juice, and maple syrup. Stir gently to ensure the blueberries are coated.

Lightly mash the blueberries in the saucepan with a potato masher until most are broken down, about 3-5 minutes.

Raise the heat to bring the mixture to a gentle boil, then reduce to low heat to simmer uncovered for about 50-55 minutes, stirring occasionally.

Conduct the cold spoon test after 50-55 minutes to check thickness. If not thickened, continue simmering for an additional 5-10 minutes.

Once thickened, remove from heat and allow the jam to cool in the pan for 10-15 minutes before transferring to a sterilized jar.