Wash the blueberries
Remove any stems, leaves, or damaged berries
Place the blueberries in a pot
Add sugar
Add lemon juice
Mash the berries slightly
Cook over medium heat
Stir frequently
Bring the mixture to a boil
Reduce heat and simmer
Continue cooking until the jam thickens
Test the consistency on a cold plate
Remove from heat
Skim off any foam
Pour the jam into sterilized jars
Seal the jars
Let the jars cool completely
Store in the refrigerator or process for shelf storage