Grenadine syrup is a sweet, scarlet colored syrup originally concocted on the island of Granada in the Caribbean from pomegranates. It has been used to add flavor and color to cocktails and even desserts. Currently, most grenadine syrups contain no pomegranate at all, and instead are made from sugar syrups, fruit flavors and red food coloring. Often found in liquor stores, they sometimes contain alcohol, too. Authentic grenadine syrup made from pomegranates is a great source for potassium.