Jelly is a great way to learn about changes of state as first it dissolves in hot water and then sets to become solid as it cools.
Why does jelly set?
Jelly sets because of a protein called collagen. Collagen is made up of three protein fibers wrapped around each other.
Jelly contains gelatin, which is made from collagen from animal bones and skin. When the gelatin is heated and mixed with water, the protein fibers unravel and come apart, so the jelly from the packet melts. As the jelly cools, the fibers coil up again, trapping water between them, which makes the jelly set.
We watched the jelly from the packet melt as we added the hot water and talked about bonds breaking down and how they reform as the jelly cools, causing it to set.
We also tried mixing different colours of jelly, which was a fun way to learn about primary and secondary colours.
To make multicoloured, layered jelly, you need to let each layer set before adding the next.
Do you know fresh pineapple stops jelly setting?
What other colours do you think we could make?
Suitable for KS1 – changes of state.
Don’t forget to check out my other kitchen science experiments.
Last Updated on May 3, 2023 by Emma Vanstone