Magic Milk Experiment

Create swirling patterns of color in milk using dish soap. You will learn how soap interacts with fats and proteins and how it breaks the surface tension of a liquid.

Materials

• paper plate (1)
• whole milk (1 glass/approx. 8 oz)
• dish soap (approx. 1 tbsp)
• food coloring (4 different colors)
• cotton swabs (2)

Safety

• Adult supervision required for sharp objects.
• Protect work surface. Materials may stain clothing.
• Adult supervision required for children under 8.

Steps

1. Pour the whole milk into the paper plate until the entire bottom is covered with a thin, even layer.
2. Let the milk sit completely motionless for 10 seconds to ensure there are no bubbles moving.
3. Carefully add a few drops of different food coloring to the center of the milk. Place the drops close to each other but try to keep the colors separated in distinct dots.
4. Dip a cotton swab into the dish soap. Wipe off any excess soap on the side of the container so it is not dripping, but still has a good amount of soap on the tip.
5. Gently touch the tip of the soapy cotton swab to the center of the milk and hold it still. Watch as the colors rapidly shoot away from the point of contact.
6. Move the cotton swab to different colored dots to see the swirling effect repeat.
7. If the reaction slows down, try using the other end of the cotton swab or start over with a fresh plate of milk for a stronger effect.