Grenadine, or a sugar syrup made from sugar and pomegranate (in a 1:1 ratio) is a common ingredient in cocktails. You can buy it, or you can make it. If you buy it, you are usually getting high fructose corn syrup, coloring, and artificial flavors. Making the real deal is easy:
1 cup white sugar
1 cup pomegranate juice
Place both ingredients in a saucepan or small pot. Place the pot on a stove element and turn the heat to high. Carefully start stirring. It won’t take long until the sugar starts to dissolve. As soon as it begins to do so, move the pot off of the heat and keep stirring. The sugar should completely dissolve within a couple of minutes. If it takes too long, you can place the pot back onto the still warm stove and continue stirring. If you leave it on the heat too long, the syrup will begin to discolor and will become bitter.
Once the liquid is clear, allow it to come to room temperature on a cool surface. When cool, add 0.5-1.0 ounces of vodka to help preserve it. Pour it into a squeeze bottle and refrigerate.