Mildew on Towels: How to Remove the Smell and Stains

That sour, musty odor that clings to a towel even after washing is one of the most common laundry frustrations, and it rarely goes away with regular detergent alone. Mildew on towels happens when moisture, bacteria, and trapped detergent residue build up in the fibers, and it takes a targeted approach to fully eliminate. Having battled plenty of funky towels over the years, I can walk you through exactly how to strip out the smell and stains and keep them from coming back. Here is the complete fix.

Why Towels Get Mildewed

Towels are the perfect breeding ground for mildew because they stay damp and absorb body oils, dead skin, and soap residue. When a towel does not dry fully between uses, or sits balled up in a hamper, mildew and odor-causing bacteria multiply fast. Over time, detergent and fabric softener residue coats the fibers and traps that smell.

The musty odor is the byproduct of this microbial growth. Killing the bacteria and stripping the residue is what actually solves the problem, not just masking it with more detergent.

The Vinegar and Baking Soda Method

The most reliable home remedy uses two cheap pantry staples in a two-cycle wash. This strips residue and neutralizes odor without harsh chemicals:

1. Wash towels in the hottest water the fabric allows with 1 cup of white vinegar and no detergent
2. Run a second wash with 1/2 to 1 cup of baking soda, again with hot water
3. Dry the towels completely on high heat, ideally in the sun

The vinegar dissolves residue and kills odor-causing bacteria, while the baking soda neutralizes any lingering smell. Do not combine the two in the same cycle, since they cancel each other out. Run them separately for best results.

Tackling Visible Mildew Stains

If you can see black or gray mildew spots, you need extra muscle. For white towels, add 3/4 cup of chlorine bleach to a hot wash, or use an oxygen bleach for colored towels to avoid fading. Pre-soaking the towels in a bucket of hot water with oxygen bleach for several hours before washing helps lift stubborn stains.

For a natural option, scrub spots with a paste of baking soda and water, or apply hydrogen peroxide directly to the stain before washing. Always test colored fabrics in an inconspicuous spot first.

Use the Hottest Water Safely

Heat is your ally against mildew. Most cotton towels can handle water up to 130 to 140°F, which is hot enough to kill bacteria and break down residue. Check the care label, but in general the hottest cycle your towels tolerate will give the best result. Cold water simply does not destroy the microbes causing the smell.

Pair hot washing with a thorough hot-dryer cycle. Towels must dry completely, since any remaining dampness lets mildew take hold again within hours.

Drying Towels the Right Way

Drying is where most people go wrong. Pull towels from the washer promptly, never leaving them sitting wet, and dry them fully on high heat. Adding clean dry towels or wool dryer balls speeds the process and fluffs the fibers. Whenever possible, hang them in direct sunlight, which naturally deodorizes and helps kill remaining bacteria.

Avoid overloading the dryer, because crowded towels dry unevenly and leave damp spots that quickly turn musty again.

Stripping Heavily Mildewed Towels

For towels that have been musty for a long time, a deep laundry strip clears built-up residue that normal washing leaves behind. Fill a tub or large sink with very hot water and add 1/4 cup of borax, 1/4 cup of washing soda, and a couple tablespoons of detergent. Soak the towels for four to six hours, stirring occasionally, and you will often see the water turn cloudy and gray as years of residue release.

Drain the tub, then run the towels through a normal hot wash with no additional detergent to rinse everything out, followed by a full hot-dryer cycle. This intensive treatment is too harsh for frequent use, but once or twice a year it restores absorbency and freshness to towels that seemed beyond saving.

When to Replace Towels Instead

Sometimes a towel is too far gone to rescue. If you have stripped, bleached, and re-washed a towel and the musty smell or stains return almost immediately, the fibers may be permanently colonized or broken down. Towels also lose absorbency over time as fibers wear, and a towel that feels thin, rough, and never quite clean has reached the end of its useful life.

Most bath towels last about two to five years with regular use before they need replacing. If yours are well past that and resist every cleaning method, it is often more practical to retire them as cleaning rags and invest in fresh ones, then apply good drying habits from day one.

Preventing Mildew From Returning

Once your towels are fresh, a few habits keep them that way. Always hang towels spread out to dry between uses rather than bunching them on a hook. Wash bath towels every three to four uses, and skip the fabric softener, which coats fibers and traps odor. Cut back on detergent too, since excess soap leaves residue.

Keep your washing machine clean as well. Run a monthly empty hot cycle with vinegar to prevent the machine itself from harboring the mildew that transfers to your laundry.

Protecting Other Linens From Mildew

The same conditions that mildew towels affect washcloths, bath mats, and shower curtains, so treat them with the same care. Bath mats stay damp the longest, so hang them to dry fully between uses and wash them weekly in hot water. Fabric shower curtains and liners benefit from a periodic hot wash with vinegar, and many can go in the machine with a couple of towels to scrub them clean.

Good bathroom habits help across the board. Run the exhaust fan during and after showers to pull moisture out of the air, and keep the room ventilated so humidity does not linger. The drier your bathroom stays overall, the less mildew has a chance to take hold on any of your linens, towels included.

Fresh Towels for Good

Getting rid of mildew on towels takes more than a regular wash, but the fix is simple and inexpensive. Strip the residue with a hot vinegar cycle, neutralize odor with baking soda, treat visible stains with the right bleach, and always dry towels completely. Then build in good drying habits and skip the fabric softener. Follow this routine and your towels will smell clean and stay that way wash after wash.