How to Make Sugar Crystals at Home

Make your own rock candy as a science experiment.

Not many opportunities to combine science and candy exist, but that's what you get when you try a basic sugar crystal experiment. The processes of precipitation and evaporation are at work in this project, according to the Exploratorium website. The site explains that children and adults can watch as approximately one quadrillion (1,000,000,000,000,000) sugar molecules grow together to form a sweet and tasty science lesson. Keep in mind that what you're seeing as the sugar crystals grow is simply the normal shape of sugar magnified.

Things You'll Need

• Measuring cup
• 1 cup water
• Saucepan
• 2 cups sugar (approximately)
• Spoon
• Pint jar
• Lollipop stick
• Coffee filter

Instructions

1. Pour 1 cup of water into a saucepan and bring it to a boil. Turn down the heat so the water continues at a low boil.

2. Stir in the sugar, one or two spoonfuls at a time. Continue adding sugar until it no longer dissolves in the pan even with constant stirring; this means the water is saturated. You may not use the entire 2 cups of sugar or you may need a bit more.

3. Rinse a clean pint jar in hot water to temper it slightly. Pour the sugar water into the jar.

4. Stand a lollipop stick in the jar. Cover the jar with an upside-down coffee filter to keep dust and flies out of the sugar mixture.

5. Watch the crystals grow, but do not disturb the jar. Sugar crystals are fragile and will break away from the stick if jarred. Wait at least seven days to see clearly defined crystals.

Tips & Warnings

• As long as you maintain sanitary conditions, your sugar crystals are edible when they mature. Add a few drops of food coloring to the sugar syrup before pouring it into the jar to produce a colorful candy.

• Find lollipop sticks at your favorite craft store or in the baking aisle of the supermarket.

• Red and green sugar crystals can be used as holiday ornaments, gifts or embellishments on a wrapped package.

References

• Exploratorium: What's Going On?
• Exploratorium: Rock Candy
• IQIO: How to Grow Sugar Crystals