Why Does My Laundry Still Smell After Washing? Causes and Fixes by Smell

Match the smell to the cause

What you notice	Likely cause	First fix	Source
Musty or mildew smell on everything	Washer has a biofilm or mold, often from a closed door	Run the washer's cleaning cycle; leave the door and drawer open	Whirlpool, LG, Abney et al.
Sour smell after clothes sat in the washer	Microbes growing in wet laundry	Rewash; move loads to the dryer right away	LG, Whirlpool
Clean clothes smell like body odor when you sweat	Body oils and odor compounds held in synthetic fibers	Warmer wash if the label allows	Abney et al.
Towels smell even after washing	Thick cotton holds water and bacteria	Warmest water the label allows; dry completely	Abney et al.
Waxy or perfume-heavy smell, stiff fabric	Too much detergent or fabric softener left in the fabric	Use the measured dose of HE detergent	LG, Whirlpool
Smell after line drying on a humid day	Slow drying lets microbes grow	Dry in the dryer or somewhere with airflow	Abney et al.

Why bacteria survive a wash

Washing removes and kills microbes in three ways: agitation and soaking, chemistry (detergent and bleach) and heat. The 2021 review says temperature plays the most important role in controlling pathogens, with temperatures above 40°C to 60°C (104°F to 140°F) needed for proper inactivation, and that detergent enzymes and bleach matter more in washes colder than 20°C (68°F) (Abney et al.). If one category of laundry keeps smelling, that's the load to wash warmer, as far as the care label allows.

The smell itself has a known culprit. A 2012 study traced the typical "wet laundry" odor largely to Moraxella osloensis, a bacterium that produces an odor compound called 4-methyl-3-hexenoic acid and tolerates drying and UV light (Kubota et al., 2012). That tolerance is why the smell can come back when a shirt gets damp again.

Fabric matters too. The review notes that bad smells are more often tied to polyester, because the odor compounds attach more strongly to it than to cotton and are harder to remove. That's why gym clothes are often the worst offenders.

Fix the washer first

If everything smells, the machine is the likely source. What the manufacturers say:

1. Run the cleaning cycle. Whirlpool says to run its Clean Washer cycle every month with its washer cleaner or liquid chlorine bleach (Whirlpool). LG recommends its Tub Clean cycle once or twice a month with an oxygen-based drum cleaner, and warns that chlorine bleach or acidic cleaners on that cycle can discolor or corrode the drum (LG). Because the brands disagree, use what your own manual says.
2. Leave the door open between loads. LG explains that front-load doors seal watertight, so keeping them shut traps moisture and residue. LG also says to let the drum and detergent drawer air out after each cycle, especially in humid weather.
3. Clean the detergent drawer. LG suggests weekly; Whirlpool says to remove and clean it regularly following your owner's manual.
4. Keep the drum empty. LG suggests using a separate laundry basket rather than storing dirty clothes in the washer.

Then fix the routine

• Move clothes out as soon as the cycle ends. Whirlpool says wet clothing left in the washer can lead to mildew, which causes odors in both the garment and the washer.
• Measure detergent. Whirlpool and LG both say to use HE detergent in HE machines and no more than the recommended amount. More soap means more residue, not cleaner clothes.
• Dry fast and fully. The review says microbes survive better at lower dryer temperatures and shorter drying times, and that they can multiply during slow air drying. Line drying outdoors in humid conditions can increase bacteria in clothing, though long exposure to sunlight may reduce fungi.
• Don't let damp clothes wait. The review's authors found bacteria grow in clothing kept in hampers between washes, more so in humid conditions. Hang sweaty gym clothes or wet towels to dry before they go in the basket.

When to rewash

If a load sat wet for hours and smells sour, rewash it before drying. If the smell keeps coming back on the same polyester items after you've cleaned the washer and changed the routine, the odor compounds may be bound to the fibers: the review notes they attach more strongly to polyester and are harder to remove with detergent alone.

A note on our sources: the 2021 review was written by University of Arizona researchers with co-authors from Reckitt, the maker of Lysol and Dettol. We used it for the science of how odors form and survive, not for product advice.