Petrichor: The Smell of Falling Rain

You may not be familiar with the word petrichor, but you know when you smell it. And you have.

Petrichor is the pleasing earthly smell that rises from dry ground when it rains. But it isn’t the smell of water per se. Instead, petrichor comes from plants and bacteria. Plants release long chain molecules called fatty acids. The chains break down into small molecules that we can smell. Soil bacteria, meanwhile, produce a chemical called geosmin. When the broken-down fatty acids and geosmin combine, you get petrichor, which is released into the air when raindrops hit the soil and the smell is carried up into our noses as a fine mist.


What is it about rain
that I can’t get enough of?
Is it the softness of rain
patting the earth,
is it the sound of
gulping throats after
a long drought, or
the sound of seeds
drinking rain, becoming
leaves, becoming trees,
the way a rivulet drinks
and becomes an ocean?
Perhaps all of these,
and oh, yes! that aroma
of dank soil still misting
in my nose as I speak.

© Wallace Fong

Leave a Reply