In a 4-quart saucepan, heat the pomegranate juice, sugar, and lemon juice on medium-high and stir it occasionally, until the sugar has dissolved and the sauce has reached a gentle simmer (about ten minutes).

Reduce the heat so that the sauce maintains a slight simmer (medium or medium-low, depending on your stove).

Continue to let it simmer for 60-80 minutes, stirring every ten minutes or so, until the sauce has reached a syrup-like consistency and lightly coats the back of a spoon. It should be reduced down to 1 to 1 ¼ cups; if you measure the sauce and there's more liquid than that, continue reducing. Don't let it reduce too much or it will become too thick and harden when it cools.

Remove from heat and let cool. You will notice the syrup has thickened after cooling.

Transfer the molasses to a glass jar and store in the refrigerator up to one month.