Underpants and odour and what lies behind it
Short answer: Odour that stays after washing sits either in the fibres or in the washing machine. The material is rarely the only cause, and both can be fixed with a few changes to how you wash and store your underwear.
Check the machine first
A washing machine with detergent residue and damp in the door seal smells on its own, and that smell passes on to everything washed in it. Run an empty cycle at 90 degrees with a little detergent, then wipe the rubber seal and the drawer. Leave the door open between washes so the machine can dry out.
Fabric softener traps the smell
Fabric softener leaves a thin film on the fibres. That film holds on to odour instead of releasing it into the water, which is why a pair of boxers can smell even after a wash. Drop the softener completely and wash the affected pairs twice in a row without it. More in washing and care.
One hot wash
A single wash at 60 degrees often resets a pair that has picked up a lasting smell. The higher temperature loosens the fats and residue that 40 degrees did not reach. Do not make it a habit, though, as the heat wears on the elastic in the waistband. Use it as a one off. See bamboo boxers for men.
Synthetics smell the most
Polyester and other synthetic fibres hold skin oils inside the fibre, where they turn rancid over time. That is the smell that stays no matter how often you wash. Cotton and viscose do this far less, because the fibres absorb water and release dirt more easily in the wash. See bamboo underwear for men.
Dry fully before storing
Underwear folded away while still slightly damp starts to smell after a week in the drawer. The moisture has nowhere to go, and that is enough for the odour to return. Let each piece hang until it is completely dry, including the seams and the waistband, where the fabric is thickest.
Do not let laundry sit
Worn underwear left for days in a closed basket gives odour plenty of time to settle. The same goes for wet laundry left in the machine after the cycle ends. Hang things up as soon as the programme finishes, and keep the laundry basket airy so moisture can escape.
Dose the detergent correctly
More detergent does not make clothes cleaner. Too much stays in the fabric and the machine, and the residue can cause a sour smell of its own. Follow the dosage on the pack for your water hardness and how dirty the load is. A drum packed full will not rinse the laundry properly either.
When a pair is finished
If you have cleaned the machine, dropped the softener and washed once at 60 degrees, and the smell is still there, it is most likely the fibres themselves. This is most common in older synthetic pairs. At that point it makes more sense to replace them than to keep trying.
In short
Odour in underwear is rarely down to the material alone. Start with the machine, drop the softener, dry things fully and use a hot wash as a one off. Choosing fibres that release dirt in the wash makes it easier to keep odour away day to day.
Frequently asked questions
Why does my underwear smell after washing?
Either the smell is in the machine, or fabric softener is trapping odour in the fabric. Clean the machine with an empty cycle at 90 degrees and stop using softener.
Does washing hotter help?
A single wash at 60 degrees often resets a piece with a lasting smell. As a habit it wears the elastic too much, so stick to 40 degrees for everyday washing.
Does bamboo smell less than polyester?
Yes. Polyester holds skin oils inside the fibre, where they turn rancid. Viscose absorbs water and releases dirt more easily in the wash, so odour settles less.
See our range of bamboo underwear for men.
