Caramilk is a popular chocolate bar sold in Canada by Cadbury Adams. Each bar is made up of many small squares of milk chocolate each surrounding a soft creamy caramel centre. In the mid-nineties, Cadbury began running a series of ads showing interesting characters like ninjas and aliens trying to solve the Caramilk secret, ending each spot with the catchy tagline “How do they get the caramel in the Caramilk bar?” Of course, Cadbury never offered an answer to this delicious mystery, but we won’t leave you hanging. Today we’re going to find out how they really get the caramel in the Caramilk bar.
Over the years, several solutions to the Caramilk problem have been proposed. One of the most popular claims that the Caramilk secret lies in an enzyme called invertase.
Did You Know? Invertase is a protein which converts sucrose (a disaccharide) into its component monosaccharides glucose and fructose in a process scientists call hydrolysis.
According to this version of the Caramilk mystery, the caramel centres found in Caramilk are made as solid, sucrose laden blocks which are laced with small amounts of invertase before being covered in melted milk chocolate. Over time, the invertase breaks down the sucrose in these blocks and the resulting glucose and water-absorbing fructose mixture softens the blocks into the creamy caramel you find in your favourite Caramilk bar.
Did You Know? Fructose molecules are hygroscopic, which means they absorb water from the atmosphere, making the resulting mixture more liquid.
This theory certainly isn’t without scientific merit. In fact, the use of invertase to soften and liquefy fondant fillings is quite common in the confectionary business. Usually, a firm fondant filling is laced with invertase prior to dipping in chocolate, so that the end result is a hard chocolate shell covering a creamy or liquid centre. If you’ve ever had a cherry cream-filled chocolate, you’ll know just how well this process works. But unfortunately for Caramilk mystery hunters, this isn’t how the caramel gets into the Caramilk bar. We know this because the ingredients list found on Caramilk wrappers do not list invertase or any other special enzyme. Unless aliens or ninjas secretly and carefully switch every wrapper on their way to the store, the invertase theory just doesn’t fly.
Did You Know? Its against the law to conceal the use of enzymes in food products, so put your conspiracy theories to rest!
So how do they get the caramel in the Caramilk bar then? The real answer to the mystery isn’t quite as exotic as you might think, but it’s no less clever. The creation of a Caramilk bar begins with an empty mould that looks like an ice-cube tray. The real secret is that the moulds are upside down—the bottoms of these moulds form the tops of the finished Caramilk bar. Melted chocolate is poured into the moulds and the sides of these moulds are chilled. Chocolate touching the sides of the mould quickly solidify, and the liquid chocolate in the centre is quickly poured out, leaving a cavity in a hard chocolate shell. The caramel filling is poured into this cavity. Then the top of the mould is cooled again so that the top layer of caramel becomes temporarily hard. Another layer of warm melted chocolate is poured into the mould and when it cools, the Caramilk bar is complete.
There you have it, the mystery of the Caramilk bar is solved, and we didn’t need any help from aliens or ninjas.
David is a PhD candidate in the Department of Medical Genetics at the University of Toronto. He graduated from UBC with a Bachelor's in Biochemistry and Computer Science. During his spare time, David helps out with local science outreach programs like Let's Talk Science.