Equipment and Ingredients Plate Cotton bud Milk Dishwashing liquid Liquid food colouring (two or more colours) Instructions 1. Pour enough milk onto the plate to cover the bottom. 2. Carefully add a few drops of each colour of food colouring onto the surface of the milk to create a polka dot effect. Notice how, the food colouring floats. 3. Dip a cotton bud into the dishwashing liquid, then hold it in the middle of the plate, keeping it as still as you can. What do you notice? Record your observations, go slow and look carefully! 4. Dip the cotton bud into the dishwashing liquid again and touch it unto a different area of the plate. What do you notice? Record your observations, go slow and look carefully! Scientists notice things and wonder what if... What happens if you use other dairy products, such as cream or trim milk, with different fat content? Does the temperature of the milk change how fast the colours mix and swirl? Do the colours mix and swirl differently if you use 1,2, 3 or more drops of dishwashing liquid in different places in the milk? How could you find out?
Based on Page 160, The Kitchen Science Cookbook by Dr Michelle Dickenson