Candy Glass Lesson

Candy Glass at a glance

Background

Have you ever wondered how glass can change from solid to liquid and back again? In this fun and tasty lesson, students will dive into the fascinating world of glass science by making their own "candy glass." Glass is a special material that doesn’t have a regular atomic structure like metals or crystals. Instead, it’s an "amorphous solid," meaning its atoms are arranged randomly, giving it unique properties.

In this experiment, students will create candy glass using simple kitchen ingredients like sugar, corn syrup, and water. As they heat the mixture, they’ll observe how it transforms from a liquid into a solid glassy state. This transition, known as the glass-liquid transition, happens because the glass's viscosity (its thickness or flow resistance) changes with temperature. By controlling the temperature and avoiding too much stirring, students can prevent crystallization and produce a hard, clear candy that mimics real glass.

Throughout the lesson, students will learn about key concepts such as viscosity, glass transition temperature, and the differences between crystalline and amorphous materials. They’ll also explore how these concepts apply to both everyday items like sugar glass and industrial materials like fiberglass. By the end of the lesson, students will understand how heat affects the properties of glass and how glass-like substances are used in various applications.

Lesson Objective

In this lesson, students will explore the science of glass by making and analyzing "candy glass," a sugar-based material that simulates the properties of real glass. They will observe how temperature affects the transition between solid and liquid states, and how these transitions are key to understanding glass processing.

Experiment Description

Students will heat a mixture of cane sugar, corn syrup, and water to create a candy glass, observing how it becomes more viscous as it reaches higher temperatures. They will then pour the molten candy into molds, allowing it to cool and solidify, and compare the properties of the finished candy glass to real glass.

Materials List

Silicon mold
Cane sugar (sucrose)
Corn syrup
Water
Saucepan or Pyrex beaker
Spoon (silicon recommended)
Bowl with cold water
Aluminum foil
Optional: Candy thermometer, food coloring, hot plate, cooking spray, parchment paper

Safety Precautions

Use oven mitts when handling hot candy glass and be cautious to avoid burns from the high-temperature mixture. Allow all equipment to cool before cleaning, and supervise younger students closely during the experiment.

The Experiment

1. Start by measuring and combining 4 teaspoons of water, ½ cup of cane sugar, and ¼ cup of corn syrup in a saucepan or Pyrex beaker.

2. Place the saucepan on a stove or hot plate and stir the mixture occasionally until it reaches a boil.

3. If you’re using a candy thermometer, insert it into the mixture to monitor the temperature, continuing to heat until it reaches approximately 300°F (150°C).

4. To test the consistency, dip a spoon into the mixture; when the syrup drips back, it should form threads. Alternatively, perform the ball test by dropping some syrup into a bowl of cold water; if it forms a hard ball and cracks when bitten into, it's ready.

5. Remove the mixture from heat and, if desired, add a few drops of food coloring and stir well.

6. Carefully pour the hot candy glass into a silicon mold or an aluminum pan lined with parchment paper or sprayed with cooking spray.

7. Allow the candy glass to cool and harden completely before removing it from the mold.

8. Finally, observe and compare the properties of the cooled candy glass to real glass in terms of appearance and texture. For cleanup, soak the saucepan and utensils in warm, soapy water to dissolve any residual candy glass, and use a paper towel moistened with hot water to clean any remaining residue from surfaces.