Crystals of Sugar

Have you ever wondered how you can grow your very own sugar crystals at home? In this activity we will make a stick of sugar crystals and we will watch the crystals grow over a few days, while learning about how crystals grow and of course what our sugar sticks taste like! This activity will introduce you to the concept of crystallization, which is the process through which crystals are made.


Crystals of Sugar

Watch the Crystals of Sugar video on the right. Subtitles are available by clicking on the icon.

Once you have watched the video, why not try the activity yourselves by downloading our recipe and instruction sheet?

Download the Instructions

The PDF below contains instructions including what is needed to complete the activity, step-by-step instructions, and a health and safety guide.

Download the Instructions

 


What are you seeing?

This activity is showing an example of crystallisation. At the beginning of the experiment, we dissolved sugar in heated water to make a solution. We added sugar until the sugar no longer dissolved because there was not enough water left to dissolve it. At this point our solution is known as a supersaturated solution and we know our solution is ready. After covering our sticks in sugar to help crystallisation, we then added them to the solution while it cooled down.

As our solution gets colder, the sugar molecules are less happy to stay in solution – this is caused by something called solubility- they would rather connect with other sugar molecules to continue growing crystals. In these conditions, when they meet other sugar molecules in the solution, they start creating a solid (the crystal) and our sugar stick starts to grow. You can learn more about what is happening in the activity in the instructions PDF above.