Colorful Milk Test
You can compare fat content in different milk products in a colorful way!
What you will need:
- Two or more milks with different fat contents. Examples: Whole milk, 2%, 1%, half & half, other types of cream, or buttermilk
- Containers – one for each different milk. Examples: saucers, small dessert plates, or small bowls
- Dishwashing liquid- Dawn works well, but good science says try others too
- Food coloring
Here’s what to do:
- Pour several tablespoons of one type of milk into one container (or enough to cover the bottom), and put a label near it so you know what kind of milk is in it, then do the same with a different milk into a different container until each different milk is in a different container.
- Start with one bowl of milk. Put a few drops of food coloring into the milk.
- Squirt a drop of dish washing liquid into the center of the milk, and watch closely.
At some point in your investigation, try putting food coloring drops in different areas of the bowl – the center, edges, groups, separate, touching, not touching, before you put in the drop of dish washing liquid. You can also try varying the amount of dish washing liquid you use.
- Try the same thing with drops of color and dish washing soap in one of the other bowls, and repeat until you’ve tested all the different types of milk the same way.
- What did you observe happening?
- What did you notice about any differences in behaviors of the different types of milk?
What’s going on?
What’s going on? It’s all about soap chasing down the fats in the milk, the same science that helps you get clean when you wash with soap! To find out more about the science in this experiment, see Explora’s “Cool Science” episode on KRQE-TV Channel 13, from July 28, 2015.
Additional science fun with food coloring and milk: Find a photo or other image of our planet, Earth, as seen from space. (Hint-search images on the internet) and then in a fresh, clean plate of milk, try dropping blue food coloring onto the milk, and using small drops of dishwashing liquid to get a swirling movement. What could the blue and white represent? Try blowing on the milk. What forces might this kind of movement represent?