My son never gets tired of this DIY rainbow milk art activity. The basic premise is to add whole milk to a pan (this is important; the fat in the milk is what makes this experiment work), then food colouring, then finally dish washing liquid. As you add the soap, the colours begin to dance and the milk transforms into a swirly tie-dyed pattern.
Read on to see how to do this experiment with your kids, and to learn the science behind it.
- whole milk (NOT low fat or skim)
- baking pan
- food colouring kit
- dish wshing liquid
- 1 adorable child
Step 1: Have your child help pour some milk into the pan (about 5 cm full).
Step 2: Squirt a little bit of each colour of food colouring into the middle. Notice that the food colouring sits virtually still on the milk.
Step 3: Now comes the fun part. Add one drop of dish washing liquid and watch the colours dance!
Step 4: Keep adding a few more drops in areas where colours are congregating. The fat particles in the milk will move away from the soap, taking colour with them.
My kids are always totally entertained by watching the colours dance in the milk.
So, what’s happening here?
Milk is mostly made up of water, but it also contains fats and proteins. The fats in the milk are super sensitive to any changes in the liquid around it. Soap weakens the chemical bond that hold the protein and fat together. The soap causes the molecules of fat to move every which way, and the food colouring allows you to see this all in action. As the soap eventually gets mixed with the milk, the movement slows down—so if you add more soap, the action will likely start all over again.
More fun kids’ activities:
- How to Make a Recycled Can Bird Feeder (Plus, 20 Recycled DIY Projects)
- 15 Crafts for Toddlers That Are Beautiful Enough to Keep
- 15 Popsicle Stick Crafts for Kids That’ll Entertain Them for Hours
Images: Liz Stanley