"Fun with Magic Milk and Food Coloring"

                       "Sick Science: Color Changing Milk"

Colourful Milk

The chemistry behind the scenes:

Milk is a homogeneous mixture of many chemical substances, elements and compounds. Among these you will find proteins (which are natural compounds found in food and in your body), fats (which are also found in food and in the body and are generally soluble in organic compounds but not in water), calcium (Ca, element #20), and other cool milky stuff.

Dish detergents are chemicals designed specifically to clean your plate of food. They contain phosphates, which are compounds that have phosphorus and can dissolve calcium, and various enzymes that break down proteins and fats to smaller particles, that can be easily washed away with water. Detergents also contain chemicals called surfactants, which lower the surface tension of a liquid and allow easier spreading.

When we add food colouring to the milk, nothing happens. But, when the dish detergent touches the milk, things start to move. The surfactants reduce surface tension, which allows the food colouring to spread around the milk. Then the enzymes start to react with the calcium, proteins and fats in the milk, which causes the colour pigments from the food colouring to get pushed around, resulting in a cool colourful pattern.

So you see, it's not magic.It's chemistry!