Food Science Fascinates Assembly

In this assembly we looked at the fascinating world of food science with some experiments that demonstrated the incredible properties of everyday foods. I was assisted by Ash (8E1) and Josie (8C3) to make ice cream using milk, ice cubes and salt. Whilst they took turns to shake a very cold bag, Alice (8D2) came on stage to help me with a second experiment.

We put a raw egg in a measuring jug and covered it with white vinegar. Alice described the white film that appeared immediately over the surface of the egg. This film was actually very small bubbles of carbon dioxide gas. As this experiment takes several days, I had two eggs that I had prepared earlier. What we observed was remarkable. The vinegar, which is an acid, (acetic acid), had dissolved the calcium carbonate found in the eggshell. The shell, which usually protects the egg, dissolved away entirely, leaving behind only a soft, translucent membrane. I think everyone agreed that the residue left in the vinegar was pretty yukky! I could see how rubbery the egg was.

We also recreated a volcano using bicarbonate of soda and vinegar, which for effect I had coloured with food colouring. Again, it was carbon dioxide that was the star of the show, with a bubbling mass of ‘lava’.

Alice helped make a bowl of Oobleck, which the students correctly identified as a non-Newtonian fluid, otherwise known as cornflour and water mixed in the correct proportions to produce a solid. Alice was able to mould in her hand then pour it back into the bowl.

Meanwhile Ash and Josie were getting very cold hands but unfortunately, the experiment was not successful, as the milk did not freeze as expected. I do hope they enjoyed trying however.

The assembly ended with me experimenting how strong the rubbery egg was and Year 8 certainly enjoyed seeing that it wasn’t as bouncy as it looked as it smashed on the floor, creating a bit of a mess. I particularly enjoyed hearing the suggestion by one of the students as he left, that I should have dropped the egg into the Oobleck to see it would protect the egg. What a show of enthusiasm and involvement!

Mrs Wenlock

Head of Food