Why Do Towels Smell Bad?

Towel odor is caused by trapped moisture in the fibers and a buildup of detergent/fabric softener residue; with the right wash-and-dry routine, you can break the odor cycle and keep towels fresh for longer.

A bad smell in towels is one of the most common laundry problems—and it is not always caused by “dirty towels.” Many people wash their towels regularly, yet the smell returns quickly. In most cases, the real cause is moisture staying trapped inside the fibers, combined with bacteria growth and product buildup from detergent or softener.

Towels are designed to absorb water efficiently. That function is exactly what makes them vulnerable: when they stay damp for too long, they become the perfect environment for odor-causing microorganisms. Poor drying conditions, repeated low-temperature washing, and residue buildup can turn a towel into something that smells “musty” even when it looks clean.

Below are the most common reasons towels develop persistent odors.

Towels Stay Wet or Damp for Too Long

The number one reason towels smell is simple: they do not dry fast enough. When moisture remains trapped inside the towel, bacteria and mildew can multiply quickly. Even if the towel appears clean, the damp inner layers can produce a strong musty or sour odor.

This problem becomes more frequent in winter, in bathrooms with poor ventilation, and with thicker towels that naturally hold more water. The longer the towel stays damp, the higher the odor risk.

Towels Are Hung Incorrectly

How you hang a towel matters more than most people think. If the towel is folded over a hook, bunched up, or stacked on itself, airflow is blocked. The outside may dry, but the inside stays wet. That trapped moisture is enough to create odor.

In small bathrooms, towels are often squeezed into narrow spaces or hung in a way that prevents full air exposure. This increases drying time and makes odor problems repeat.

Towels Are Used Too Often and Washed Too Late

Towels do not only absorb water. They also collect body oils, sweat, dead skin cells, and sometimes cosmetic residue. With frequent use, this buildup increases. If the towel is not washed soon enough, bacteria feed on these residues and odor becomes stronger.

This is especially noticeable during summer, in humid climates, or when towels are used after workouts. The longer the washing interval, the faster odor develops.

Low-Temperature Washing and Weak Hygiene Performance

Washing towels at low temperatures all the time can leave behind oils and residues that do not fully break down. Low-temperature washing is not always “wrong,” but for towels—especially those used daily—it can become a problem when combined with heavy use.

Even when a towel looks clean, leftover residue inside the fibers can accumulate over time and create odor. This is why some towels smell “clean at first” but quickly turn unpleasant after one or two uses.

Using Too Much Detergent and Leaving Residue Behind

More detergent does not mean a cleaner towel. Excess detergent often stays trapped in the fibers, especially if the machine cannot rinse it out completely. This buildup coats the towel, reduces airflow through the fabric, and creates an environment where odor-causing bacteria can thrive.

A typical sign of detergent buildup is this: the towel smells fine right after washing, but develops a heavy smell soon after drying or reuse.

Fabric Softener Causes Absorbency Loss and Odor

Fabric softener can make towels feel softer in the short term, but it often leaves a coating on the fibers. That coating reduces absorbency and prevents the towel from releasing moisture properly. As a result, towels stay damp longer—and damp towels smell.

Over time, softener buildup can create the “clean but still smelly towel” problem, because the odor source is inside the coated fibers rather than on the surface.

Towels Sit in the Washing Machine Too Long After the Cycle Ends

Leaving towels inside the washing machine after the cycle finishes is one of the fastest ways to create odor. The machine is warm and humid, and towels stay in a closed environment where bacteria multiply quickly.

In some cases, that smell becomes stubborn and does not disappear easily, even after rewashing. Removing towels immediately after washing is one of the simplest habits that prevents odor.

Towels Are Not Dried Properly

Washing towels is only half the process. Drying is just as important. If towels are folded and stored before they are completely dry, odor can become permanent. Moisture trapped in storage continues feeding bacteria and mildew.

Drying towels indoors in a space with little airflow also increases drying time, which raises the risk of musty smells.

The Washing Machine Itself Is Dirty

Sometimes the odor is not coming from the towel—it is coming from the washing machine. Detergent drawers, rubber seals, and drum areas can build up slime, detergent residue, and mildew over time. This transfers unpleasant smell to towels during washing.

In this situation, towels may come out “washed” but still smell bad, because the machine environment is contaminating them.

Hard Water and Mineral Buildup

Hard water can cause mineral deposits to build up inside towel fibers. This makes towels feel stiff, reduces absorbency, and increases odor risk. Mineral buildup can also prevent detergent from dissolving properly, which increases detergent residue and worsens odor problems.

Hard water often creates a cycle where towels become less absorbent, stay damp longer, and smell faster.

Towel Thickness and Fabric Structure Can Increase Odor Risk

Some towels are naturally slower to dry because they are thicker, denser, or highly absorbent. These towels can perform well, but only if drying conditions are strong enough. When drying is poor, thick towels are more likely to develop odor.

Lower-quality towels can also lose fiber integrity faster, which may make them hold odors more easily over time.

Why Does Towel Odor Become Persistent?

Once odor becomes embedded, normal washing may not fully remove it. This happens because the odor source is often deep inside the fibers, not just on the surface. Detergent residue and softener buildup make it easier for odor to stay trapped.

Persistent odor is usually the result of repeated habits: damp storage, weak washing cycles, residue buildup, and slow drying all reinforce each other.

Towel odor is usually not a “dirt problem.” It is a moisture and buildup problem. Towels smell when they stay damp too long, when detergent and softener residues accumulate, when drying is insufficient, or when the washing machine itself carries mildew and odor.

If the smell keeps returning, the solution is not just washing more often—it is improving the full routine: washing method, drying conditions, and long-term fiber cleanliness.