This Color Changing Milk Science Experiment is a fun activity to do with kids of all ages. Science experiments help us grow. Through experimenting and exploring we are able to ask questions, make assumptions, and then seek solutions. We are able to learn more about the world around us.

Color Changing Milk Science Experiment (text) over a brightly colored pan of milk with food coloring in the colors of yellow, blue, red and purple - Kids Activities Blog
Let’s do a fun science experiment today!

Color Changing Milk and Dish Soap Experiment

Let’s explore surface tension through this simple science experiment that doubles as an art activity for kids of any age.

Related: More easy science experiment for kids

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What you need for the Milk Food Coloring Experiment

Directions for Magic Milk Experiment

Watch Science Experiment Video

Step 1

Pour milk  a pie pan or glass bowl until it covers the bottom.

Step 2

Add drops of liquid food coloring to create a colorful pattern.

Step 3

Step 3 - Color Changing Milk experiment in action - child hand with q-tip touching colorful liquid
Look how the colors scatter and move!

Dip a Q-tip in dish soap and place it in the center of the dish. Watch as the food coloring moves away!

Tips for Teaching Magic Milk Science Experiment

color changing milk experiment - text: milk + food dye + dish soap = colorful experiment
This science experiment is so fun!

Our Science Question:  

What do we think will happen when we add dish soap (a surfactant – i.e. it cuts grease and fats) to the milk?   How can we watch the surface tension “break”?

The Science Behind the Experiment:  

  • Surface tension is an interesting concept, like molecules like to stick together. 
  • Milk has surface tension, just like water, but unlike water, it is high in fat and is solid colored.
  • As the dye is less dense, it does not mix into the milk unless stirred. It remains separate.  
  • Dish soap breaks down the fat of the milk and decreases the surface tension in milk.

Tips for Science Experiment:  

If you have gel dyes add a few drops of water onto them to help them be absorbed more quickly.

More Science Questions to Ask

  • What did the milk look like when you added  the dye? Why do you think that is?
  • What happens when you add the soap?   Why did the “dyed milk” disappear?   Where do you think it went?
  • Why did the colors return after the experiment has been running for a while?

Related: Things to make with soap

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What did your kids learn in the magic milk experiment?

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