Step 1

Place a small plate in the freezer.

Step 2

Combine blueberries, lemon zest, lemon juice and sugar in a large pot. Heat on medium to high heat.

Step 3

Stir blueberries frequently.

Step 4

Once blueberries come to a boil and cook for an additional 10-15 minutes on medium heat. The blueberries should start to slightly thicken.

Step 5

Remove plate from freezer and add a small spoonful of blueberry jam. Place plate back into the freezer for 1-2 minutes. Remove plate from freezer run a finger through the jam if it stays separated and doesn't run your jam is done.

Step 6

Remove jam from heat. Spoon jam into mason jars leaving about 1 inch of space at the top of the mason jar. Let jam come to room temperature then refrigerate or freeze jam.