Reference point
Open the door of a room closed for months and smell the first breath of air.
Do this before you read on. An entry only works when you have just smelled the thing.
Damp, musty, dusty, with a note of old paper and a layer of wood. It rushes out when the door opens, then thins within a few minutes.
This is the smell of stagnant air, built from mould on the walls, organic dust, and substances slowly released from wood, paper and fabric. No single component dominates; it is the mixture itself that makes the character.
Ten minutes after the door is opened the smell is almost gone. It exists only in the closed state.
How to smell it
Open the door of a room that has not been used for a long time and stand on the threshold, smelling the first rush of air. Come back ten minutes later — almost nothing is left.
Why this one is hard
Because it is associated with dirt and damp, so the first reaction is to throw the door wide open — destroying exactly what you need to smell.
Don’t confuse with
This entry
Musty storeroom
Earthy family
A storeroom may contain trichloroanisole, giving a damp-rag, old-paper note; leaf litter has geosmin and mushroom alcohols, giving a living earthy note. One is dead, the other decomposing.
Scientific note
No single compound represents this smell. It is a mixture: geosmin and 2-methylisoborneol from bacteria on damp walls, volatiles from moulds, and whatever is slowly released from wood, paper and fabric.
Some rooms also contain 2,4,6-trichloroanisole, produced when microfungi transform chlorine compounds in building materials or anti-mould treatments. It stands out because its detection threshold is among the lowest ever measured — a few parts per trillion — so a tiny amount is enough to dominate. It is also the compound behind corked wine.
But it is a possible component, not the definition of this smell.
In Vietnamese life
This is a smell many people associate with old houses, attic rooms and the belongings of someone who has died. It has an unusually strong power to call up memories for its modest chemical complexity.