The Science behind Cooking Sugar

–Houston, TX

A Tasty and Informative Experiment

We all enjoy one kind of candy or another, whether it be fudge, caramel, lollipops, or taffy. But have you ever wondered how your favorite sweet is made? The answer most likely lies in the stages of cooking sugar syrup.

The Different Stages of Cooking Sugar

There are seven different stages of sugar, depending on the highest temperature it reaches while cooking. The higher the temperature reaches, the harder the sugar will be when it cools. The first stage of sugar is the thread stage, which happens around 230 degrees Fahrenheit. In this stage, the sugar syrup spins a loose short thread used for icings, syrups, or dessert décor. The next stage, reached when the sugar is 234 degrees, is the soft ball stage. This stage is named after the texture of the sugar, which forms a soft sticky ball. This stage is often used for caramel, fondant, and buttercream. The next two stages, firm ball and hard ball, are very similar to the previous stage. Forming at 244 degrees and 250 degrees respectively, the sugar becomes either a firmer but pliable ball, or a hard ball. These stages can be used for toffee, merengue, caramels, or nougat. The next two stages, soft crack and hard crack, are where the sugar really begins to change. At 270 degrees, the soft crack stage forms stiff but still pliable strands of sugar used for butterscotch and taffy. At 300 degrees, the hard crack stage forms firm and brittle strands, used in many hard candies. The last stage–the caramel stage–is reached at 320 degrees and is similar in texture to the hard crack stage, but with a characteristic amber brown color.

Sugar can be used for many different types of candy and many diverse textures can be achieved, depending on the temperature, as seen above. But why does the texture of sugar change after being heated, and remain even when it is cooled down?

Condensation Reactions in Sugar

Table sugar, also known as sucrose, is a disaccharide made up of glucose and fructose. This means that it is made up of two simple sugars linked together to make a complex sugar. When sucrose is heated with water, a condensation reaction occurs, meaning that two hydrogens (H) and an oxygen (O) leave the sugar to form water as steam. When an OH and an H leave sucrose to become water during this reaction, sucrose is left with a missing bond. Thus, it bonds with itself to become stable once again. As sugar reaches higher temperatures, and more water leaves the sugar, it interlocks with itself more and more. This interlocking raises the viscosity of the sugar, causing the stiffer texture as sugar is heated more. This new texture remains even after cooled, because the water has left the sugar and the bonds remain even after cooling.

Now that we understand what makes sugar, let's try it out! Make sure to do this experiment with a trusted adult because the sugar gets very hot, and it can be a bit messy.

Materials:

• A saucepan (one you don't mind getting dirty)

• A food thermometer

• 3 ½ cups sugar

• 7 tablespoons water

• 7 cupcake liners

Steps:

1. Mix ½ cup sugar and 1 tablespoon water in saucepan

2. Heat on low to medium heat, stirring occasionally with thermometer, until reaches desired temperature

3. Remove from heat and carefully pour mixture into cupcake liner and let cool

4. Observe your sugar!

Temperature Listings:

• Thread stage- 223 to 234 degrees Fahrenheit

• Soft ball- 234 to 240 degrees Fahrenheit

• Firm ball- 242 to 248 degrees Fahrenheit

• Hard ball- 250 to 266 degrees Fahrenheit

• Soft crack- 270 to 290 degrees Fahrenheit

• Hard crack- 295 to 310 degrees Fahrenheit

• Caramel- 320 to 360 degrees Fahrenheit

Now we know what makes the different stages of sugar, and how these correlate to different types of candy. Maybe next time you can use one of these stages to make your own favorite dessert. As always, stay curious!

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