rock candy syrup

Originally (19th Century and possibly earlier), rock candy syrup was probably the sugar syrup in which crystalized rock candy was made. Eventually, this byproduct became a product, itself: a liquid sweetener for use in place of disagreeably hard sugar cakes or later, granulated sugar. For practical intents and purposes, rock candy syrup is just name for version of sugar syrup, although some commercial examples may include of a hint of flavoring. There’s no standard for the sugar concentration of “rock candy syrup” so you must account for that uncertainty in recipes calling for it.