You see it. The air shifts. Something rises from the ground, earthy and alive, and you know rain is coming before a single drop has fallen.
That scent has a name. Petrichor. And the story of the word begins, fittingly for us, in Australia.
What petrichor means
Petrichor is the earthy scent released when rain falls on dry ground. The word was coined in 1964 by two Australian scientists, Isabel Joy Bear and Richard Thomas, in a paper published in the journal Nature.
They built it from two Greek words. Petra, meaning stone. Ichor, the fluid said to flow through the veins of the gods. The essence of stone. The blood of the earth.
It is rare for a smell this universal to have a name this precise. Rarer still that the name is Australian.
The science of the smell
Pure rainwater is almost odourless. The scent does not come from the rain. It comes from what the rain disturbs.
The main source is geosmin, a compound produced by bacteria living in the soil. It builds up in dry earth, then releases into the air when raindrops strike the ground, carried up on a fine mist.
The human nose is extraordinarily attuned to it. We can detect geosmin at concentrations as low as a few parts per trillion. Plant oils and a trace of ozone complete the scent, but geosmin is its heart.
Why we love it
There may be something ancient in the response. Rain meant survival to those who came before us. The scent that promised it may be written into us, a relief felt before it is understood.
That is the feeling. Not nostalgia as sentimentality, but recognition. A knowing that happens before thought. The body remembering something the mind cannot name.
The parfum that holds the rain
Perfumers have long tried to capture petrichor. It resists. Geosmin is difficult to source and harder to blend, and most attempts smell of the idea of rain rather than the thing itself.
We made Petrichor Plains for the moment the storm finally breaks. A welcomed relief from prolonged abstinence. Drenched from the sky, an invigoration of wood and earth, asphalt and ash.
Iris and rain at the top. Violet, rosemary and cardamom at the heart. Amyris and Australian Sandalwood at the base. Dormant rock and aching fields entering the ether and resting on skin.
It is for the one who feels the land. Who has stood in the middle of a paddock and smelled the rain before it arrived. Who belongs to country. Worn on the first cool day after heat, it is a return. A relief. The moment everything releases.
Petrichor Plains is part of our Series Two, dedicated to the rare phenomena of the Australian landscape. You can read more about that origin in our guide to Australian parfum, and about its 30% strength in what 30% concentration actually means.
Frequently asked questions
What is petrichor?
Petrichor is the earthy scent released when rain falls on dry ground. The term was coined in 1964 by Australian scientists Isabel Joy Bear and Richard Thomas, from the Greek petra, meaning stone, and ichor, the fluid of the gods.
What causes the smell of rain?
The scent comes mainly from geosmin, a compound produced by soil bacteria, released into the air when rain strikes dry earth. Plant oils and a trace of ozone add to it. Pure rainwater itself is nearly odourless.
Is there a parfum that smells like rain?
Yes. Mihan Aromatics Petrichor Plains is built around the scent of rain on dry Australian earth, with notes of iris, rain, violet, rosemary, cardamom, amyris and Australian Sandalwood.
Why do humans find the smell of rain pleasant?
One theory is evolutionary. Rain was essential to the survival of our ancestors, so the brain may respond to its scent with an ancient, almost primal sense of relief.
Is petrichor the same as the smell of ozone before a storm?
Not quite. Ozone is the sharp, almost metallic scent produced by electrical activity before a storm. Petrichor is the warmer, earthier smell produced when rain actually meets dry ground.
What notes are in Petrichor Plains?
Top: iris and rain. Middle: violet, rosemary and cardamom. Base: amyris and Australian Sandalwood. It is a 30% parfum, vegan, and handmade in Melbourne.
Familial scents of Australia. Explore the collection at mihanaromatics.com.
