Pomegranate molasses is pomegranate juice that has been cooked down (reduced) to a syrup consistency. It has a sweet-and-sour flavor and is delicious in everything from desserts to grilled and roasted meat. Check the international aisle of your supermarket, look near the syrups or baking ingredients in a specialty food store, or buy it online. Once opened, it will keep indefinitely in the refrigerator.