Why Does Air Taste Different After Rain?

When you walk outside after a dry spell ends and smell that fresh, earthy air, you are smelling geosmin. This is a chemical made by tiny bacteria living in the dirt. They produce it like a snack or a warning signal. When raindrops hit the dry ground, they act like tiny poppers. Each drop traps a bit of air containing these chemicals and shoots them up into the sky. You breathe this in and think you are smelling 'wetness,' but water itself has no smell. The scent is actually coming from the soil being shaken loose by the rain.