Bring the pomegranate juice, sugar, and lemon juice to a simmer in a saucepan over medium-high heat. Once the sugar has dissolved, reduce the heat to medium-low, and simmer until the juice has reduced to 1 1/2 cups, about 1 hour. Stir the molasses frequently as it thickens to keep it from burning. When the molasses is done, allow it to cool to room temperature, then pour into a glass storage container, and keep in the refrigerator.
