Are bacteria the cause of towel odors? How to prevent unpleasant odors

Once a towel starts to smell, it's hard to get rid of it. Many people are probably worried that "I washed my towels thoroughly, but when they get wet they smell bad" or "No matter how many times I wash them, I can't get rid of the smell."

I think many people are bothered by the fact that even though they didn't notice the odor right before using the towel, the odor becomes strong as soon as they use it to dry their hands or body and it gets wet.

The cause of unpleasant odors from towels is dirt that remains on the towel and bacteria that grow on it. When the odor gets worse, it becomes impossible to remove it by simply washing and drying the towel.
Also, although the smell is not very noticeable when the towel is dry, it becomes stronger when it absorbs moisture, so you should not let your guard down just because the towel does not smell after washing.

This time, we will introduce the causes of unpleasant odors in towels, how to prevent towels from becoming smelly, and what to do if your towels do start to smell.

What causes towels to stink?

The reason why towels smell even after being properly washed repeatedly is because of dirt such as sebum and protein that has stuck to the towel and not been completely removed, and the odor that is produced when bacteria break down these dirt.

Today's washing machines and detergents are so powerful that you might think they will remove dirt without any extra effort, but in fact the degree to which dirt is removed and how much remains will vary depending on the type and amount of items being washed.

Thick items such as towels are especially prone to stains even after thorough washing, and although you won't notice it with daily washing, dirt will accumulate little by little with each use and washing.

The dirt left on the towel becomes an ideal source of nutrition for the bacteria that exist in our living environment, and bacteria attach to the surface of the skin and from the air, multiplying, and produce an unpleasant odor by breaking down the dirt.

There are several types of bacteria that produce unpleasant odors, but the most common is Moraxella bacteria (hereinafter referred to as Moraxella), which produces an unpleasant odor similar to that of a rag dried indoors.

Other bacteria known to cause this include Micrococcus bacteria (hereinafter referred to as Micrococcus), which gives off a sweaty smell that is reminiscent of sports club lockers, and Staphylococcus aureus, which gives off an ammonia smell.

Moraxella bacteria, which smells like a rag

Moraxella bacteria, which is often the cause of odors in towels hung to dry indoors, is a type of normal bacteria that is found everywhere in everyday living spaces, including the human body. It is said to be resistant to dryness and ultraviolet rays, and the bacteria itself will not be killed by simply washing it in the washing machine and hanging it outside.

Moraxella bacteria easily grow in the presence of moisture, so if you dry clothes indoors, where they take a long time to dry, they will grow using the remaining dirt as nutrients and produce an unpleasant odor.

Micrococcus bacteria that causes sweaty odor

The "sweaty" smell often experienced in sports club locker rooms is said to be caused by the proliferation of micrococcus bacteria.

Micrococcus bacteria are also a type of bacteria that normally reside on human skin and grow in the presence of dirt and moisture. They break down oily dirt, particularly sebum, and produce an odor known as "sweat-like odor."

Causes of odor other than bacteria

I mentioned earlier that the main reason towels smell is because bacteria break down remaining dirt, but in fact the smell comes from the remaining dirt itself.

One type of stain that cannot be completely removed by washing is sebum stains, which react with oxygen in the air and produce a unique odor. This odor is common in long-worn underwear and old clothes, and is the same odor of oxidized sebum as the odor of aging and manly body odor.

How to keep towels from smelling bad

The reason towels smell is not the bacteria themselves, but the presence of dirt that serves as nutrients for bacteria to grow. A brand new towel with no dirt on it will not smell even if it is wet and hung to dry indoors. This is because there is no dirt to serve as nutrients for bacteria, and so even if bacteria adhere to it, they cannot grow.

In other words, the way to prevent towels from smelling is to wash them thoroughly and remove any dirt.
You don't have to do anything special; just make sure to thoroughly remove any dirt, be careful not to leave any behind, and wash it a little more carefully, and you'll be free from unpleasant odors.

Specifically, set the amount of water to a level that you think is just a little too much for the amount of towels you're washing, add the correct amount of detergent based on the amount of water, wash the towels thoroughly on a high spin cycle that makes them move up and down, and rinse thoroughly.

For fully automatic washing machines, use about half the maximum washing capacity, set the water level to the maximum, and select "rinse with water" or "rinse three times." The most important step in washing is "rinsing," and the more water and number of rinses, the less likely dirt will remain.

Since it is often not possible to adjust the amount of water used with drum-type washing machines, we recommend selecting a setting with a longer rinse time, such as the "thorough cycle," or adding one or two sets of rinsing and spin-drying after the wash is complete.

Be sure to use the right amount of detergent and bleach as necessary. It is best not to use fabric softeners, etc. Do not use leftover bath water.

After washing, take out the clothes promptly and hang them out to dry. The inside of the washing machine is humid and is an environment where bacteria and mold can easily grow, so never leave them there. This is very important. If you have a drum-type washing machine, we strongly recommend that you dry it out.

When drying towels, it is important to dry them as quickly as possible.
If you dry it outside, do it in a shady area with good ventilation. If you dry it indoors, do it in a place where the air conditioner or fan will blow on it to avoid creating conditions that are conducive to the growth of bacteria.

What to do with smelly towels

Towels get smelly because bacteria break down dirt and produce an unpleasant odor, so the problem can be solved by removing the bacteria and dirt.

From here, we will introduce you to a method to restore smelly towels to their original condition by disinfecting them and removing stubborn stains.

1. Heat in a microwave to sterilize

The bacteria that cause odors are sensitive to high temperatures, so they are almost completely killed by heating in the microwave.

Wet the towel with water, wrap it in plastic wrap, and microwave it at 500W for about 1 minute. Remove it, let it cool, and then wash it as you normally would to remove the odor.

However, if the towel itself is not clean, the odor may return.

2. Disinfect and deodorize with bleach

・For white items

For white towels, soak them in a basin or other container of water, add the specified amount of chlorine bleach, and soak for the specified amount of time, then wash as usual.

Chlorine bleach is very effective and breaks down bacteria and dirt, so the odor is almost completely eliminated.

If the smell is too strong, you can increase the amount of bleach a little, but be careful not to overdo it as it can damage the fabric.

Be sure to soak the item for the specified time. After soaking, be sure to wash it separately from other laundry.

・Colored and patterned items

For colored or patterned items, you cannot use chlorine bleach, but you can use oxygen bleach.

Fill a washbasin or similar with the hottest water your water heater can produce, add the specified amount of oxygen bleach, and soak the clothes for the specified amount of time, then wash as usual.
If the odor remains, repeat the soaking and washing process.

Oxygen bleach cannot break down stubborn stains, so if any stains remain, the odor may reoccur.

3. Boil the towels

Boil water about 10 times the weight of the towel in a large pot (about 1 liter for one face towel), add a small amount of laundry soap (soap, not detergent!) or a small amount of oxygen bleach and the towel, and boil for 3 to 10 minutes over low heat. Turn off the heat and let it cool, then wash as usual.

If the stain is not severe, it will be effective without adding detergent or bleach.
The heat sterilizes the material and makes it easier to remove stubborn dirt, eliminating odors and making them less likely to reoccur.

However, please note that in rare cases, heating may cause discoloration or fading.

Stubborn stains that cannot be removed by washing can be removed more easily by applying heat.

This method is particularly effective against oily stains, and can remove not only odors caused by bacteria, but also odors caused by the oxidation of oil and fat.

The reason why soap is recommended over detergent is that the higher the temperature of soap, the better its cleaning effect, and it does not contain ingredients that produce foam or fragrances.

Summary

The best thing to do is to prevent odors from occurring in the first place.

The cause of unpleasant odors from towels is dirt that has adhered to or remains on the towel, and bacteria such as Moraxella and Micrococcus that use this dirt as nutrients to grow.

In particular, Moraxella and Micrococcus are normal resident bacteria, so even if you use the methods we have introduced to remove odors, if dirt gets on the towel, they will multiply again and cause odor again.

Dirt becomes harder to remove over time, so be sure to wash used towels frequently to remove dirt as soon as possible and keep them clean.