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How is candy made?

Updated: Feb 24, 2019

By: Amanda Zheng

It’s November 1st. Your stomach is aching from all the Halloween candy devoured last night, and you are regretting the tons of chocolate, caramel, and lollipops you have consumed. But even in your misery, have you ever wondered about how those Halloween candies are made? #timeforastory


The basis of all candy is... you guessed it, sugar! The most common type, sucrose, actually represents two sugar molecules bonded together, a glucose and fructose. But the candy you get from your arduous trick or treating hardly taste like table sugar, so what’s the difference? To make these treats tasty, candy scientists #mydreamjob utilize various chemistry concepts to create different tastes and textures.


If you’ve ever made rock candy on a stick, then you’re familiar with the concept of crystallization. The process begins with a supersaturated solution, often created by boiling sugar in water. To create the desired crystals, a stick is inserted into the mixture and the unstable solutes of the supersaturated liquid will freeze into intricate shapes resembling crystals. However, there are other candies in which crystallization must be prevented, such as caramel, toffee, and marshmallows. In order to achieve this, brown sugar, fats, or acids are added into solution to prevent any crystallization process.


That perfect golden brown color with the unique lingering sweet smell always makes my mouth drool in anticipation. In order to make the delicious caramel, sugar syrup is heated to the point of caramelization at around 320 - 350 F. At this point, the sucrose molecules split into glucose and fructose, resulting the delicious flavor in hard caramel candies that can make us salivating. To make the soft, chewy caramels like the ones in our beloved Milky Ways and Twix bars, you have to add milk, cream, or butter.


But there are more types of candies than just rock candy and caramel. In order to make these unique textures, a sugar solution is heated to certain temperature which causes unique property. At 106-112 C, the thread stage is achieved in order to create rock candy. At 112-115 C, the soft ball stage is used to make fudge. At 116- 120 C the firm ball stage is used to create caramel and marshmallows. At 122-130 C, the hard ball stage is used to make a toffee-look-alike found in delicious Heath bars. At 132-143 C the soft crack stage is used to make butterscotch. At 146 – 155 C, the sugar reaches its hard crack point in which lollipops and nut brittle are made. Lastly, at 160-182 C at the caramel point, the sugar forms the delicious treat we know and love.

To explore more science concepts hidden in candy, check out this link by the American Chemical Society!



[1] Husband, Tom. (10/2014). The Sweet Science of Candymaking. ACS. . Retrieved: 10/28/2018.

[3] Candy Science – The Chemistry Behind Candy Making With Delicious Recipes. Steam Powered Family. . Retrieved: 10/28/2018.


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