Grow Your Own Rock Candy

Create delicious sugar crystals on a stick to explore the science of supersaturation. You will learn how sugar dissolves in hot water and crystallizes as it cools down.

Tools

• pot (1)
• spoon (1)
• stove or hot plate (1)

Materials

• water (1 cup / 240 ml)
• sugar (3 cups / 600 g)
• wooden chopstick (1)
• clothespin (1)
• glass jar (1)

Safety

• Adult supervision required for hot materials. Burn risk.
• Adult supervision required for sharp objects.
• Adult supervision required for children under 8.

Steps

1. Heat one cup of water in a pot on the stove until it starts boiling and bubbling.
2. Slowly pour in the sugar a little bit at a time, stirring constantly with a spoon.
3. Continue adding sugar and stirring until no more sugar will dissolve into the water.
4. Remove the pot from the heat and let the sugar-water solution cool down to room temperature.
5. Dip the wooden chopstick in water, then roll it in a small amount of dry sugar to create a starting surface for crystals.
6. Place the chopstick inside the jar, ensuring it is suspended and not touching the bottom of the glass.
7. Secure the chopstick in place using the clothespin clipped to the rim of the jar.
8. Have a grown-up helper pour the cooled sugar solution into the jar, leaving some room at the top.
9. Place the jar in a safe spot and wait one to two weeks for the crystals to grow and harden into rock candy.