Fragrance is a chemical mixture, and three things break it down: light, heat, and oxygen. Most people store their perfume somewhere that supplies all three.

The three enemies

Light, particularly direct sunlight, breaks down aromatic molecules and discolours the liquid.

Heat accelerates every chemical reaction in the bottle, including the unwanted ones. Temperature swings are worse than steady warmth.

Oxygen enters as the bottle empties, which is why a half-used bottle degrades faster than a full one.

Where not to keep it

The bathroom — the worst place in the house, and where most people keep it. Hot, humid, and with a large temperature swing every time someone showers.

A windowsill or dressing table in sunlight. Bottles are designed to look attractive on display, which is precisely the wrong place for them.

A car, in any season.

Near a radiator.

Where to keep it

A cupboard or drawer, at stable room temperature, in its original box. The box is not packaging to be discarded — it is light protection, and manufacturers include it for that reason.

A cool, dark, dry cupboard is genuinely all it needs.

Refrigeration

A wine fridge or dedicated cool box at around 12–15°C is ideal for a large collection. A kitchen fridge is not recommended — too cold, too humid, and the temperature shock every time you take it out is its own problem.

For most people, a dark cupboard is entirely sufficient.

How long it lasts

Unopened and well stored: several years, often much longer.

Opened: three to five years for most, sometimes less.

Longevity varies by composition. Citrus and light fresh fragrances turn fastest — their volatile top notes degrade first. Orientals, woods and heavy bases can last a decade or more, and some improve.

How to tell it has turned

  • Colour change, usually darkening
  • A sour, sharp or vinegary opening where there was brightness
  • The top notes gone entirely, so it smells only of the base
  • Cloudiness

A turned fragrance is not dangerous, but it will not smell as intended, and it can irritate skin.

Practical habits

  • Keep the cap on. Evaporation and oxidation happen through an open neck
  • Do not decant into a container that is not airtight
  • Buy smaller bottles of light fragrances you wear rarely, since they will turn before you finish a large one

For choosing what to buy in the first place, see the perfume section.