How to Remove Mildew Smell From Towels for Good

September 9, 2026

Wash once on hot with two cups of white vinegar and no detergent, then again with half a cup of bicarbonate of soda. Two separate cycles, never mixed together.

Why the smell is there

Towels that smell are usually coated rather than dirty. Detergent used generously and fabric softener used at all leave a residue that builds up over months. That residue is slightly waxy, it reduces how much water the cotton can absorb, and it holds damp against the fibre where bacteria multiply. The smell appears when the towel gets wet and those bacteria become active again, which is why a towel can smell fine dry and foul the moment you use it.

The two cycle reset

  1. Cycle one. Hottest wash the towels tolerate, two cups of white vinegar, no detergent, no softener. The acid dissolves the alkaline residue.
  2. Cycle two. Repeat hot with half a cup of bicarbonate of soda and nothing else. This neutralises the remaining odour compounds.
  3. Dry completely. Full heat in a dryer or full sun outdoors. A towel that is nearly dry is a towel that will smell again by tomorrow.

Running vinegar and bicarbonate in the same load is a common mistake. They neutralise one another and you get a load washed in salty water.

Why it comes back

Habit Effect
Too much detergent Residue that traps moisture
Fabric softener Waxy coating, reduced absorbency
Overloading the machine Nothing rinses properly
Leaving the load wet Bacteria establish within hours
Folding a damp towel A sealed damp environment

The machine itself

If the reset works and the smell returns within a fortnight, the washing machine is the source. Front loaders in particular collect biofilm in the door seal and the detergent drawer. Wipe the seal dry after use, run a hot maintenance wash monthly, and leave the door ajar between loads. A machine that smells will transfer that smell to everything it washes, and no amount of work on the towels will fix it.

Ongoing habits that keep them fresh

  • Use roughly half the detergent the box suggests. Dosing instructions assume heavily soiled loads.
  • Hang towels spread out rather than folded over a rail, so both faces dry.
  • Wash every three or four uses rather than weekly by habit.
  • Skip softener entirely. If towels feel stiff, a small amount of vinegar in the rinse softens them without coating.

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