When you put a can of Coca-Cola in a pot of boiling water, the soda will bubble and hiss like it’s alive. But what exactly is happening inside the can?

The answer lies in the chemistry behind the soft drink. When you add water to Coke, you’re breaking down its two main ingredients — sugar and carbonated water. The resulting reaction creates carbon dioxide gas and releases a bubbling sound as well as a nearly invisible cloud of CO2 that floats out of the can.

Coke gets its carbonation from carbon dioxide (CO2) molecules dissolved in water. As soon as they’re exposed to heat or pressure, those CO2 molecules start moving faster and eventually escape into the air — creating bubbles that rise to the surface and pop on contact with air. That’s why shaking a soda can before opening it causes more fizz than opening it without shaking!

Last modified: September 7, 2022