Well, one of the sweet syrups that they used was Grenadine syrup, but the Grenadine they used had about the same relationship to the stuff we have as the Maraschino cherries they used have to ours -- they're similar, in some sort of sense -- if you've had the real thing, you can sort of taste what the modern thing is TRYING to do -- but, they're not very close at all. (A "maraschino cherry", by the old definition, is a sour cherry marinated and stored in a thick syrup/paste mixture of Maraschino liqueur and sugar. Luxardo still manufactures them, and if you see a jar, pick one up -- they're really rather good.)
Grenadine is a very easy syrup to make: one part sugar to two parts pomegranate juice. You can add a couple drops of orange blossom water, but it's not strictly necessary. The only reason, as far as I can tell, that the real stuff fell out of favor is that, for decades, you just couldn't GET pomegranate juice in the United States. But now that we all love our antioxidants, there's no reason to use the Rose's Artificial Stuff any more. Well, unless you want to, I guess.
So, I decided to make some, for the first time. I put the sugar and pomegranate juice into a pot, and set the flame on reasonably high to get it simmering. Once it started simmering, I reduced the flame and simmered it for about a half hour, until it had reduced and thickened somewhat. I changed the heat a few times, and did do a full boil for a couple minutes to caramelize the sugar; in the future, I'm not sure if I'd do that. The darker caramelized sugar flavor tastes more like the Rose's stuff we're used to, but it overpowers a lot of the pomegranate flavor. I was tasting it as I went (using a new teaspoon each time -- I'm sanitary), and it was coming along nicely.
Eventually, it finished, and I poured it into a glass bottle for storage.
Then I put the bottle in the sink, not noticing the puddle of water, and the jar cracked, and my quart of Grenadine went down the drain.
Oh, well. At least it was down the drain rather than on the floor.
(x-posted to xiphias)