Let’s dive into the sparkling world of edible glitter! Try this activity to make your own bedazzling treat and explore secret shapes in food.
Safety: This activity involves using a stove and handling a hot object. Ask an adult to help. Use clean hands and clean equipment while cooking.
You will need
- 1 cup water
- 1 tablespoon cornflour
- Food dye (colour of your choice)
- A non-stick pan or pot
- 2 sheets of overhead projector (ohp) transparencies or acetate paper
What to do
- Pour one cup of water into a non-stick pan or a pot.
- Add one tablespoon of cornflour to the pan or pot. Then, stir the mixture with a spatula until it looks like a milky liquid.
- Use medium heat to start cooking the cornflour mixture. Keep stirring the mixture with a spatula for about 10 minutes until it thickens to a gel-like consistency.
- Pour the gooey mixture into a bowl and add a few drops of food dye to it. Mix the dye into the cornflour paste with a spatula. You should start with one or two drops and slowly add more until you get the colour you like. You can also mix different colours together.
- Scoop out the coloured mixture and use a spatula or spoon to spread it thinly over the ohp transparencies or acetate paper.
- Leave the mixture to dry into a firm but flexible sheet. This may take 2-3 days.
- Remove the dried cornflour sheet from the acetate paper. Use a blender to blend the dried cornflour sheet until it becomes glitter sized. Make sure your blender is completely dry before you start! Store your glitter in an air-tight container in a dry location out of direct sunlight.
When you mix the cornflour with water over heat, the cornflour granules will gradually absorb water and swell. Then, the granules will burst from absorbing all the water and release starch molecules. These molecules stick together and form the gooey gel.
As the gooey gel cools, the starch molecules start to reorder and recombine themselves into different shapes. This process is called “retrogradation” (retro-grah-day-shun). During retrogradation, some of the absorbed water in the starch molecules will be released, which leads to more of the starch molecules shuffling around and reforming into smoother shapes. If you’ve ever tasted stale bread, then you’re familiar with retrogradation.
When the starch paste dries up, the starch molecules will all reorganise themselves into special shapes that give them a shiny appearance. As the ohp or acetate paper is usually very smooth and doesn’t absorb water, this means that the cornflour paste will dry more completely and more smoothly, allowing for more light to be reflected. This creates a shiny surface, perfect for glitter.