Science Course with Ryan Morse: Cocoa powder, from wet to dry in an instant

(WFRV) – Cocoa powder is a common household item. It can be used from anywhere from making chocolate milk to baking a cake. You may have seen this experiment online, but check out how you can do it right at home.

Do it yourself experiment

Materials: cocoa powder, a drinking glass filled with milk, a spoon, and a toothpick.

Steps:

1. Get a spoonful of cocoa powder
2. Slowly drop the spoonful of cocoa powder into the milk, without turning it over
3. Pull the spoon out after a couple seconds
4. Take a toothpick and poke the wet the cocoa powder

Whoa! The cocoa powder seems to instantly dry. You can even drop the powder into the milk multiple times and it will still work.

What is really going on?

The explanation is pretty simple to this phenomenon. Cocoa powder is hydrophobic which means it does not dissolve easily into water.

By poking the outer layer with a toothpick, you are essentially breaking the outer layer of liquid, similar to popping a balloon.