Thursday, August 2, 2012

Color changing milk

Today we experience something really awesome :))!!! We investigated an experiment mixing milk, food colouring and two drops of dishwashing liquid. The result was magical, an explosion of colours!!!! My son loved it!!!!

All you need is milk (whole or 2%), food colouring (red, yellow and green), dishwashing liquid, dinner plate and cotton swabs.


1st step: Pour milk in the plate enough to cover the bottom.

2nd step: Add a few drops of each colour of the food colouring in the middle of the plate. I used green, yellow and red, but you can add more colours if you wish.

3rd step: Put two drops of dishwashing liquid on the cotton swab, and place it the centre of the place holding for 10 seconds. As soon as it touches the mixture it starts to move.

Place the cotton swab at different parts of the plate to see what happens; it continues to move :)). The colours moving and mixing together gives an amazing effect. We really really enjoyed it!!!!!

To explain the science behind this experience I will copy what is explained at Steve Spangler Science website.

How does it work?

Milk is mostly water but it also contains vitamins, minerals, proteins, and tiny droplets of fat suspended in solution. Fats and proteins are sensitive to changes in the surrounding solution (the milk).
The secret of the bursting colors is the chemistry of that tiny drop of soap. Dish soap, because of its bipolar characteristics (nonpolar on one end and polar on the other), weakens the chemical bonds that hold the proteins and fats in solution. The soap's polar, or hydrophilic (water-loving), end dissolves in water, and its hydrophobic (water-fearing) end attaches to a fat globule in the milk. This is when the fun begins.
The molecules of fat bend, roll, twist, and contort in all directions as the soap molecules race around to join up with the fat molecules. During all of this fat molecule gymnastics, the food coloring molecules are bumped and shoved everywhere, providing an easy way to observe all the invisible activity. As the soap becomes evenly mixed with the milk, the action slows down and eventually stops. 
Try adding another drop of soap to see if there's any more movement. If so, you discovered there are still more fat molecules that haven't found a partner at the big color dance. Add another drop of soap to start the process again.

We had a lot of fun investigating this experiment. Hope you enjoy it too :))))!!!!!


  1. this experiment is the funnest one I know.

  2. Yes, it is super cool :)))!!! Glad you like it too!!!!