The Boiling Point

After I'd been making lollipops for a while, I leafed to the Confectionery chapter in my copy of Harold McGee’s On Food and Cooking and read something that I no doubt learned in high school chemistry class years ago: adding dissolved molecules of something to pure water will raise its boiling point.

As McGee says, "The more foreign molecules, the higher the boiling point." Syrup, of course, consists of dissolved sugar molecules in water. As more of the water boils off, the syrup becomes ever more concentrated, and its boiling point becomes even higher. Nearly all of the water must be boiled off for the syrup to reach the temperature needed for making hard candy (~302 degrees F).

In practical terms, I realized that if I started with less water in the pan in the first place, it could take less time to make a batch of lollipops because there'd be less water that needed to boil away during the process. Neat, huh!