Your towels came out of the wash an hour ago. They're clean. So why do they smell like a wet dog left in a gym bag?
That musty, sour smell isn't because your towels are dirty. It's because bacteria and mildew have set up camp deep inside the fibres — and your normal wash cycle isn't reaching them. The fastest way to remove mildew smell from towels is a two-cycle wash: one hot cycle with white vinegar (no detergent), then a second hot cycle with baking soda. It takes about 90 minutes and works on even stubborn odours.
Below, you'll get the exact method, why it works, and — more importantly — how to stop the smell from coming back.
Why Your Towels Smell (Even After Washing)
Mildew smell in towels comes from bacterial biofilm — a thin, sticky layer of microorganisms that forms inside the loops of terry cloth when the fabric stays damp for too long. (Mildew, by the way, isn't the same as mould — mildew is the flat, powdery growth you see on the surface, while mould penetrates deeper into fibres and appears as dark, fuzzy patches. The smell usually starts as mildew and gets worse if left untreated.) According to microbiological research on household textiles and bacterial growth, bacteria begin multiplying within hours on a damp towel, and once they've formed a biofilm, they release waste compounds that produce that familiar sour, stale odour — even on freshly washed fabric.
A regular wash cycle with detergent can't break through that biofilm. Worse, three common habits actually feed the problem:
- Too much detergent. Excess soap doesn't rinse fully from thick towel fibres. It leaves a residue that traps moisture and gives bacteria something to feed on.
- Fabric softener buildup. It coats fibres with a waxy, silicone-based layer that reduces absorbency and prevents towels from drying completely — exactly the conditions mildew loves.
- Overloading the washer. Stuffing too many towels in one load means they can't move freely. Water and detergent don't circulate properly, so residue stays trapped in the fibres.
- Leaving towels in the machine. Even 30 minutes of sitting in a warm, damp drum after the cycle ends is enough for mildew to take hold.
How Do You Get Mildew Smell Out of Towels?
The most effective method uses two separate wash cycles — one with white vinegar, one with baking soda. They work on different chemistry: vinegar (acetic acid) kills the bacteria and dissolves mineral deposits, while baking soda (sodium bicarbonate) neutralises the odour molecules left behind. You run them separately because mixing the two cancels out their effectiveness.
Knowing how to wash towels properly makes the difference between towels that smell fresh for days and ones that go musty within hours. Here's the step-by-step:
Cycle one: vinegar
- Put your smelly towels in the washing machine — nothing else. No detergent, no softener.
- Add one cup (240 ml) of plain white vinegar to the detergent dispenser.
- Run the hottest cycle your machine offers. Hot water loosens the biofilm that traps bacteria in the fibres.
Cycle two: baking soda
- Leave the towels in the drum — don't remove them.
- Sprinkle half a cup (120 g) of baking soda directly onto the towels.
- Run the hottest cycle again. No detergent, no vinegar this time.
Drying
Remove the towels the moment the second cycle ends. Dry them immediately — either in a hot tumble dryer or outside in direct sunlight. UV light is a natural antimicrobial, so line drying in the sun does double duty. The key: don't let them sit damp. That's exactly what caused the problem in the first place.
What If the Smell Won't Budge?
For towels with deeply set mildew — the kind where you can see grey or black spots — try soaking them in a basin with one cup of vinegar and a tablespoon of bicarbonate of soda for 30 minutes before running the two-cycle wash. If the spots are still there after treatment, the mildew has damaged the fibres. At that point, the towel has done its job. Time to let it go.
One more thing: if every towel in your household smells musty regardless of washing, the problem might be your machine. Front-loaders are especially prone to mould buildup around the door seal. Run an empty hot cycle with two cups of vinegar once a month to keep it clean.
How Do You Stop Towels Getting Musty in the First Place?
Fixing the smell is straightforward. Preventing it from returning takes a few small habit changes — none of them difficult, all of them worth it.
| Habit | Why it matters |
|---|---|
| Hang towels spread out on a bar | Air circulates; towel dries in hours, not days |
| Skip fabric softener | Removes waxy coating that traps moisture in fibres |
| Use half the detergent | Less residue for bacteria to feed on |
| Move towels to dryer within 15 min | Prevents mildew from taking hold in the drum |
| Wash every 3–4 uses | Doesn't give bacteria a head start |
| Toss in wool dryer balls | Softens fibres and speeds drying without chemicals |
Here's what each of those looks like in practice:
- Hang towels spread out, not bunched. A towel folded over a hook dries at the fold and stays damp in the middle. Use a towel bar or rail where the fabric can hang its full width. Air circulation is the single biggest factor.
- Skip the fabric softener. Permanently. It coats towel fibres with a silicone-based film that reduces absorbency and traps moisture. Your towels will actually feel softer without it over time — the fibres won't be weighed down by residue. If you want softness, toss in a wool dryer ball instead.
- Use half the detergent you think you need. Towels are thick and absorbent, which means they hold onto soap. Most people use far more detergent than necessary. Half a dose is usually plenty.
- Don't leave towels in the washer. Set a timer if you need to. Move them to the dryer or the line within 15 minutes of the cycle ending.
- Wash towels every three to four uses. Waiting longer than that gives bacteria too much of a head start — especially in humid bathrooms.
If you're interested in how to care for linen or other natural-fibre textiles, the same principles apply: less detergent, no softener, and prompt drying.
When Is It Time to Just Replace Them?
Even well-cared-for towels don't last forever. Most cotton towels hold up well for two to three years of regular use — after that, the loops flatten, absorbency drops, and the fibres become more porous, which makes them harder to fully dry and more prone to harbouring bacteria. If your towels feel thin, take ages to dry you off, or smell musty again within a day of washing, they've reached the end of their useful life.
When you do replace them, think about your bathroom as a whole. Towels are one of the easiest ways to refresh the feel of a bathroom — a considered colour palette and quality fabric make more of a difference than most people expect.
Sometimes the fix is simply new towels. Browse our bath collection for pieces that look as good as they feel.
