Why clothes smell and how to make clothes smell good

Ever wondered why clothes have a musty smell after washing? Or why clothes sometimes smell for no reason? Our experts reveal the science behind why clothes smell.

8 July 2019

Clothes hanging in wardrobe
Clothing Care

When you’ve got that favourite outfit ready – whether it’s for a night out on the town or a chilled day with the family – you want to feel your best. So there’s nothing worse than reaching for your clothes from the wardrobe and noticing an unexpected wiff. We reveal the science of why your clothes can smell for unexpected reasons – and how you can stop it from happening.

What causes clothes to smell bad?

There are several factors at play that can cause an odour in clothes and other textiles:

  • Secretions and bacteria on the skin. The transfer of body odour from the skin to the clothes is an obvious cause of clothes smelling. Fresh sweat doesn’t actually smell – but it does contain some molecules that are broken down by enzymes and bacteria to produce those odours we’re all familiar with. Bacteria that live on the skin can also cause smells by converting any ‘food’ (that's things like skin secretions, dead skin cells leftover organic stains like food and even residual products such as lipstick and laundry products)into energy so they can grow. This process produces smelly compounds as a waste product.
  • Bacteria on the clothes. Dirt on clothes is another obvious reason for clothes to smell. Things like bodily fluids can introduce other smells, bacteria and ‘food’ to the mix. When you wash your clothes, particularly dirty garments may also 'contaminate' the rest of the load.
  • Material type. Some textile types are more prone to retaining odours than others. Because of their molecular structure, Lycra is the worst, followed by polyester - while cotton is generally better. Lycra and polyester are hydrophobic, which means they hate water so the odours stick to them. Furthermore, Lycra is designed to be a bit like a sponge, so it traps odours inside it. Cotton is hydrophilic, which means it likes water and therefore the odours don’t stick – however this causes other problems…

Why can clothes smell bad after washing?

You may think washing clothes will clean them – but it can also introduce odours. Here’s why:

  • Sometimes the washing process isn’t completely effective. This could be because the temperature is too low, the cycle wasn’t long enough, the drum has been overloaded or the type of the material hasn’t been considered.
  • If the clothes aren’t completely clean, then bacteria and ‘food sources’ remain and further metabolism continues during drying. This can cause bad odours, and is worse if the clothes are allowed to dry slowly by being left in the machine or in high humidity. If there’s a lot of cotton in the load, it carries a huge amount of water which can also slow the drying process, encouraging smells to form.
  • Washing machines aren’t always clean themselves – they’re a breeding ground for bacteria and mould. These – as well as smells generated in the machine - can be transferred to the clothes during the wash.
  • Materials like Lycra and polyester can retain smells in and on the fibres. These smells might not seem obvious after washing, as they are released during wear as the fabric warms up – such as during exercise.
  • Musty smells can reappear if clothes are stored for a long time, as bacteria and fungi recover from the shock of drying and slowly grow on the fabric.

How to prevent clothes smelling

Don’t worry – there are ways to ensure your clothes don’t smell by following these simple tips:

  • Don’t leave finished laundry damp in the machine. Remove it and dry as soon as possible.
  • Speed up the drying process after the wash - line drying is best if possible. If you don’t have much space to dry your clothes, separate out the items that will take longer, such as jeans and towels.
  • Keep your washing machine clean and hygienic by:
  • Running a high-temperature cycle (60C or 90C) without clothes. Use a biological powder containing bleach – like Persil Bio powder - to clean out the machine drum.
  • Wipe the rubber door seal monthly to remove trapped water, slime and debris.
  • Remove the fabric conditioner drawer monthly and give it a thorough clean with hot water and detergent.
  • Leave the washing machine door open after a wash to allow it to dry out naturally.
  • Find out more on how to clean a washing machine.
  • For sports gear and Lycra, try to wash them soon after exercise.

How to treat smelly clothes

Despite your best efforts, you may still find that clothes smell – but there are solutions:

  • For musty-smelling cotton clothes, such a towels and jeans, the simplest solution is to re-wash and dry quickly.
  • For smelly sports kit, wash with a biological powder containing bleach for a bit longer than normal. Even if you wash at 30C, this should remove stubborn odours.
  • Washing at a higher temperature for longer will also help remove odours - but always refer to the washing instructions on the fabrics.
  • For really stubborn odours, pre-soak in a bucket with concentrated detergent. You can do this by using the standard dose of biological powder with four litres of water.