Scald storage bottle in boiling water, drain well, and place on its side in a 215-degree F. oven to dry out. Dip bottle lid and funnel into boiling water and drain on a clean paper towel. Combine juice and sugar in a small saucepan, or a 1–pint glass measuring cup. Stir to dissolve the sugar completely. Bring to the boil, either on the stove or in the microwave (about 5 minutes in a 1100-watt oven), and cook uncovered until reduced to 3/4 cup (6 fl.oz.). The result should weigh 6.5 oz.wt.
Using a paper coffee filter tucked in the funnel, strain the syrup into a hot, dry bottle. Let cool, then cap or cork (new cork only) the bottle and store in the refrigerator. Keeps indefinitely if you wipe the bottle carefully after each use.
Yield: about 3/4 cup (6 fl.oz.) of 1.08 specific gravity syrup (same as Rose’s, based on our calculations from Rose’s Nutrition Facts label)
POM Wonderful’s POM Syrup recipe, but with quantities adjusted for a more stable product
The one drawback with this Grenadine is that the color is darker than commercial versions, and muddies the hue of our Surf Rider.
http://macheads2.net/recipes/Grenadine.html