The Milk Rainbow

🌈 What is it about?

Drop food coloring in milk, touch the surface with a soap-dipped cotton swab and watch the colors move like magic. A surprising and incredibly easy science experiment.

👶 Recommended age: 2–7 years
⏱ Estimated time: Less than 1 hour
💪 Energy level: Low
💰 Approximate cost: Low

🛒 Materials needed

• Whole milk (works better than skim)
• Food coloring in various colors
• Liquid dish soap
• Cotton swabs
• A shallow plate or dish

🛒 Food coloring set

🏠 Home alternatives

Don't have all the materials? No problem.

• Instead of food coloring → use watercolor paint diluted in water.
• Instead of whole milk → cooking cream or coconut milk also work.
• Instead of a cotton swab → use a wooden toothpick with a drop of soap on the tip.

📋 Step-by-step instructions

1. Pour milk into the plate until the bottom is covered.
2. Add drops of different colored food coloring at different spots.
3. Dip the tip of the cotton swab in dish soap.
4. Gently touch the center of a drop of food coloring with the swab.
5. Watch as the colors explode and move on their own.

💡 Extra ideas

• Try with cold and warm milk to see if there is a difference in movement.
• Touch different spots on the plate to create different patterns.
• Explain to your child that the soap breaks the fat in the milk — that's what makes the colors move.

🎥 Example video

Watch tutorial