Clothes that smell like mildew after going through the washing machine were left wet in the drum too long before drying. Running them through a second wash with regular detergent will not remove the smell, because detergent cannot kill the mold spores that have colonized the fabric fibers.
The smell comes from live mold, not from residue. Standard laundry detergent removes dirt and surface odor but requires an antimicrobial agent to actually kill mold spores. Without that, the second wash refreshes the clothes and the smell comes back within hours of wearing them.
The vinegar rewash method
Run the affected clothes through a full wash cycle using one cup of white vinegar in place of detergent. No detergent, just vinegar. The acetic acid in white vinegar kills mold spores at the fiber level rather than washing around them.
Use a warm or hot water setting appropriate for the fabric. Cold water reduces the effectiveness of vinegar against mold. The full cycle length matters because the vinegar needs sustained contact time with every part of every garment.
For severe mildew smell that has been through the dryer multiple times, use the two-cycle method. Run the vinegar cycle first to kill the spores, then run a second cycle with your regular detergent. The first cycle kills the mold and the second cycle removes the residue and vinegar smell.
When baking soda is the better option
Baking soda works as an alternative when vinegar isn’t available. Mildew is acidic and baking soda is alkaline, so half a cup of baking soda added to the drum disrupts the mold’s chemical environment and neutralizes the odor compounds. It’s less effective than vinegar at killing spores directly but works well enough for mild mildew smell.
You can find the full range of laundry fixes, including how to handle other common odor problems, in the guide on laundry tips that actually work. Musty towels are a closely related problem with a slightly different cause, and the approach in the guide on getting musty smell out of towels uses the same vinegar principle with a few additional steps specific to thick terry fabric.
The prevention step that matters most
Transfer clothes to the dryer within 30 minutes of the wash cycle finishing. Most modern washing machines have a damp alert or end-of-cycle notification for exactly this reason. Leaving clothes sitting wet in a closed drum for more than an hour consistently produces mildew smell, regardless of the detergent or water temperature used.
If you regularly forget to move clothes, set a phone reminder when you start the wash. It sounds obvious, but the habit gap is almost always the cause. A single cycle left overnight in the drum can produce mildew smell strong enough that two vinegar rewashes are needed to fully clear it.
When the washing machine is the actual source of the smell
If clothes come out of a fresh wash already smelling musty, the washing machine itself is the problem. Mold grows inside the drum, gasket, and detergent drawer of front-loading machines in particular. Clean clothes going through a moldy machine pick up the smell during the cycle.
The guide on how to clean mold out of a washing machine covers the drum cleaning cycle and gasket scrub that removes the internal mold completely. Until the machine is clean, the vinegar rewash method will only partially work because the clothes are being recontaminated during each wash.
For eco-friendly laundry products that perform well without harsh chemicals, the eco-friendly cleaning products guide includes several options tested against standard alternatives. And if you want a full cleaning system rather than individual fixes, When You Were Never Taught to Clean covers the foundational habits that make every room easier to maintain. It’s $11.99 and available immediately.
A washing machine cleaner tablet from Amazon run monthly prevents mold buildup inside the drum before it starts transferring to clothes. The tablets take 60 seconds to use and cost less than a dollar each. Building that into the weekly cleaning schedule as a monthly task means you rarely deal with the problem at all.
The fix for mildew-smelling clothes is always the same: vinegar kills the mold, and stopping the wet laundry from sitting overnight prevents it from coming back.
