Reference point
Walk past a stretch of road being surfaced, smelling downwind.
Do this before you read on. An entry only works when you have just smelled the thing.
Burnt, dense, oily, with a mineral layer. Very heavy, and it clings to clothes for a long time.
This entry belongs entirely to the city and is entirely man-made. Asphalt is the last residue of petroleum distillation — the heaviest molecules left after everything lighter has been taken off.
That makes it a perfect example of the base stage: what is left after everything else has evaporated.
How to smell it
Walk past a site where asphalt is being laid and stand downwind a few dozen metres away. Don’t go close — hot asphalt fumes contain many substances that should not be inhaled directly.
Why this one is hard
Because it is hard to catch at the right moment, and because you have to keep a safe distance.
Don’t confuse with
This entry
Hot asphalt
Smoky & Mineral family
Straw smoke is sweet, with plant resins; asphalt is burnt, dense, entirely mineral and without any sweetness.
Scientific note
Hot asphalt releases polycyclic aromatic hydrocarbons, of which naphthalene is the easiest to recognise. They evaporate significantly only when hot, so a cold road surface has almost no smell. It is one of two entries in the dictionary whose smell comes entirely from petroleum.
In Vietnamese life
For many people born in Vietnamese cities, the smell of hot asphalt goes with summer noons and with the city spreading outwards. It is one of the few smells in this dictionary that did not exist at all before the twentieth century.