This fun experiment is a classic for a reason! In the magic milk experiment, kids learn about simple chemical reactions and physical properties using only a few ingredients. Read on to see how to do the experiment, and fill out the form on this page to grab your free recording sheet.
How does the magic milk experiment work?
In this experiment, you pour some milk in a shallow dish. You then add drops of food coloring to the surface of the milk. Using a cotton swab dipped into dish soap, you lightly brush the surface of the milk. The dish soap breaks the surface tension of the milk, and the soap molecules try to attach to the fat molecules in the milk. This causes swirls and bursts of fun rainbow colors.
What does the magic milk experiment teach?
This experiment teaches us about the science of molecules and how substances interact. The soap breaks down the fat molecules and makes them move apart, showing us a simple but fascinating example of chemistry in action!
Materials needed
To do the magic milk experiment, you will need a shallow bowl or plate, milk, blue dish soap, cotton swabs, and food coloring. Our free recording sheet is also helpful—fill out the form on this page to grab it. Be sure to use the more inexpensive food coloring as opposed to gel coloring, which does not work as well.
Magic milk experiment steps:
1. Pour milk into a shallow dish or bowl, just enough to cover the bottom.
2. Add drops of food coloring all over the surface of the milk.
3. Dip the end of a cotton swab into a separate dish of blue soap.
4. Lightly brush the top of the milk with the cotton swab, and watch what happens!
Grab our free magic milk experiment worksheet
Fill out the form on this page to get your worksheet. The worksheet asks kids to guess the correct order of the steps in the experiment. Next, kids must make a prediction about what they think will happen. They can use the provided spaces to draw what happens before and after they add the dish soap. Did their predictions come true?
Additional reflection questions
- What happened when we added the soap to the milk?
- Why do you think the colors appeared on the milk’s surface?
- What do you think would happen if we added more soap to the milk?
- What do you think would happen if we used a different liquid instead of milk?
Can the magic milk experiment be done for a science fair?
Yes! If you want to do the magic milk experiment for a science fair, we recommend switching up some of the variables. For example: Does the fat content of the milk matter? Does the type of dish soap? Make a hypothesis about how changing the variables will impact the experiment. Good luck!