When blueberries are in season, make blueberry jam!
In a saucepan over medium heat, combine blueberries, sugar, lemon zest, and juice, stirring well and mashing about ¼ of the berries. Continue to cook for about 30 minutes or until thick. Pour into hot, sterilized jars, leaving a ¼-inch headspace. Seal and process for 20 minutes in a boiling water bath.