1. Rinse the blueberries in cold water without soaking them.

2. Place blueberries in preserving pan with the sugar and lemon juice. Bring to a simmer.

3. Pour simmering mixture into a ceramic (or glass) bowl. Cover with parchment round and transfer to refrigerator. Refrigerate overnight.

4. The next day, transfer mixture to a large pot and bring to a boil over high heat, stirring gently.

5. Continue to cook over high heat for 5 to 10 minutes, stirring and skimming as necessary.

6. Check set (mixture should reach 221 degrees).

7. Pour the jam into sterilized jars, filling to the fill line. Repeat process with remaining jars. Put lids and rings on jars and tighten; do not overtighten. At this point, jam may be kept refrigerated up to 1 month.