Color Changing Milk!

Steve Spangler’s Science Website offers a ton of wonderful science experiments for kids. One of my favorite experiments that Steve Spangler does is Color Changing Milk! Blogs like A Bit of This and A Bit of That and SMMART Ideas talk about this fun and popular experiment, too! Here is what you do: 

Materials:

• 2% or Whole Milk
• A dinner plate
• Red, yellow, green, and blue food coloring
• Dish washing soap (Steve Spangler recommends using Dawn) 
• Q-Tips

Directions:

1. Pour milk in the dinner plate (enough to fill the whole plate and completely cover the bottom).
2. Add one drop of each color of food coloring in the milk. Try to keep the drops close together, but not so close that they are already mixing with one another.
3. Take a clean Q-tip and dab the end of it into some dish washing soap.
4. Place the end of the soap-covered Q-tip into the middle of the milk. Hold the Q-tip there for about 10 seconds. All of a sudden, the colors in the milk will quickly begin to swirl together!
5. You can reapply Q-tips  with dish soap and try this as much as you want in your colorful milk mixture!

So how does this simple, but fun experiment work? Milk contains protein and tiny amounts of fat in it. Both fat and proteins are very sensitive to chemical changes. The chemicals in the dish soap weaken the chemical bonds that hold the protein together in the milk solution. The food coloring allows us to visibly see the changes in the protein molecules. Also, the soap molecules cause the fat in the milk to mix and swirl until the fat has been distributed across the entire amount of milk.