In a huge, wide, uncovered pan, heat pomegranate juice, sugar, and lemon juice on medium high until the sugar has disintegrated and the juice stews.
Decrease heat barely enough to keep a stew.
Stew for about 60 minutes, or until the juice has a sweet consistency, and has decreased to 1 to 1/4 cups.
Assuming you need your pomegranate molasses to be better, add more sugar to taste, while you are cooking it.
Empty out into a container. Let cool. Store chilled in the cooler.