Why does jelly set?
It is because of a protein called collagen which is found in our bodies. Collagen is made up of three protein fibers wrapped around each other.
Jelly contains gelatin, which is made from collagen which comes 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.
So, down to the fun bit for younger children. 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 it cools making it set.
We also did some colour mixing and made some multi-coloured jelly.
We had to let each layer set before adding the next for the multi-coloured version.
Did 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 our other kitchen science posts.