Many of us have experienced taking clothes out of storage only to be greeted by a musty, moldy smell. This unpleasant odor can linger in fabrics and be difficult to remove. But what causes this smell in the first place?
There are a few key reasons why clothes develop a musty smell after being stored for a period of time. The main culprits are moisture, bacteria growth, and the fabrics themselves. Understanding what leads to the musty odor can help you prevent it from happening in the future.
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Reason 1: Moisture
Moisture is one of the biggest contributors to musty smelling clothing. When clothes are packed away in closets, basements, attics or storage containers, they can come into contact with moisture in a variety of ways:
- High humidity or damp environments allow moisture to seep into fabric fibers
- Storing clothes while still damp or wet from washing
- Condensation and temperature fluctuations introduce moisture into storage areas
This moisture gets trapped within the fabric fibers and allows for odor-causing bacteria and mold to thrive. The moisture also reactivates odors in the fabric that detergent failed to completely remove.
Here are some tips to prevent moisture buildup when storing clothes:
- Allow clothes to fully dry before packing them away
- Use storage containers designed to keep moisture out
- Place moisture absorbing products like silica gel packs in storage containers
- Store clothing in a dry environment with relatively stable temperature
Controlling moisture is key to keeping clothes fresh smelling in storage. Small amounts of moisture can lead to big musty smells over time.
Reason 2: Bacteria and Mold Growth
Musty odors are largely caused by microbes like bacteria and mold growing on stored clothes. The right conditions allow these odor-causing microbes to multiply quickly:
Ideal conditions for bacteria and mold growth:
- Warm, humid environment with poor airflow
- Presence of dirt, dust or food particles on fabric
- Moisture trapped within fabric fibers
During storage, bacteria feed on organic matter stuck on clothing, producing smelly byproducts. Mold also releases odor molecules that give clothes that characteristic musty smell.
Once bacteria and mold colonize on fabric, they can be very difficult to fully eliminate. The key is preventing microbe growth from the start.
Here are some tips for deterring microbes when packing clothes for storage:
- Wash clothes thoroughly before storage to remove dirt, sweat and other contaminants
- Use storage containers that allow for air circulation and prevent humidity buildup
- Add cedar blocks or sachets to storage containers – their aromatics naturally repel microbes
- Avoid overcrowding clothing – allow space for air to circulate
With extra care taken to deter bacteria and mold, clothes can be stored without taking on a musty stench.
Reason 3: Fabric Type
Certain fabrics are more prone to developing musty, moldy smells than others when stored. These fabrics tend to hold moisture and odors more readily:
- Natural fibers like cotton, linen, silk
- Synthetic blends containing polyester, nylon or spandex
- Thick, heavy fabrics like wool sweaters and coats
The structure and materials that make up these fabric types can contribute to that post-storage musty smell.
Why these fabrics retain odors:
- Absorb and trap moisture easily
- Attract dust and dirt particles
- Hold onto odors from sweat and products like deodorant
- Provide favorable environments for mold and bacteria
On the other hand, some fabrics resist odors and hold up better to storage. These include:
- Synthetic materials like polyester, nylon, acrylic
- Fabrics with moisture wicking finishes
- Tightly woven fabrics like denim
Being aware of how your various fabrics respond to storage conditions can help you take steps to prevent musty smells. For example, you may want to store wool separately from cottons and linens with extra odor absorbers.
How to Remove Musty Smells from Clothes
If clothes already have a musty or mildewy odor, there are a few ways to tackle the smell:
- Wash thoroughly – Use the warmest water recommended for the fabric and add a sanitize cycle or extra rinses if possible. Detergent alone may not eliminate odors that have built up over time. Add vinegar, baking soda or an odor eliminating additive to the wash.
- Air dry in the sun – The heat and UV rays of sunlight have natural deodorizing and disinfecting properties. Let clothes dry thoroughly outside if possible.
- Steam clean – A garment steamer can help remove musty smells trapped in fabric fibers using the power of hot steam.
- Store with baking soda – Place clothes in a sealable bag or bin with opened boxes of baking soda for a couple days. The baking soda will help absorb lingering odors.
- Use activated charcoal – Charcoal is very effective at trapping odors. Add charcoal bags to clothing storage containers or seal smelly clothes in a bag with loose charcoal pieces for a day.
With some time and effort, you can usually eliminate a musty smell from clothes. But prevention is always better – be sure to store clothes properly to avoid the odor issue altogether.
How to Prevent Musty Smells When Storing Clothes
Here is a summary of tips to keep clothes fresh smelling in storage:
- Wash and fully dry clothes before packing away
- Use breathable storage containers that deter moisture and allow airflow
- Add cedar, charcoal or baking soda to absorb odors
- Avoid overcrowding clothing; leave space to circulate air
- Store in clean, dry areas with stable temperature
- Check periodically for signs of moisture or odor
- Take clothes out of storage occasionally to air out
With proper storage habits, your clothes can stay smelling clean and fresh until their next wear. A few precautions go a long way in preventing that dreaded musty odor.
The Science Behind Musty Smells
The unpleasant musty or moldy smell that develops on stored clothes is caused by microbial metabolites. Here is a more detailed look at the science behind the odors:
Microbes Causing Musty Odors
The two main types of microbes responsible for the musty smell are bacteria and mold fungi:
Bacteria
Common bacterial species that grow on fabrics and release smelly byproducts include:
- Bacillus
- Staphylococcus
- Pseudomonas
- Proteus
- Clostridium
Mold
Some mold genera known to colonize on damp fabrics are:
- Aspergillus
- Penicillium
- Cladosporium
- Alternaria
- Chaetomium
With ideal conditions, populations of bacteria and mold can thrive on clothing, leading to odor issues.
Musty Odor Causes
The specific molecules emitted by bacteria and mold growing on clothes give rise to the characteristic musty smell. These include:
Bacterial metabolites:
- Hydrogen sulfide – rotten egg odor
- Ammonia – urine-like smell
- Indole – fecal odor
- Skatole – feces smell
- Putrescine – rancid/decayed smell
Mold metabolites:
- 1-octen-3-ol – earthy, mushroom odor
- 3-Octanol – moldy, mildew smell
- Geosmin – damp, musty smell
Some odor molecules have very low detection thresholds, meaning only tiny amounts are perceptible to the human nose. As few as 10 bacterial or mold spores per square inch on clothes can lead to a detectable musty smell.
Impact of Humidity and Temperature
Two environmental factors that strongly influence microbe growth and musty odors are humidity and temperature.
Humidity
- Mold requires moisture to proliferate and release odors
- High humidity speeds up bacterial growth and byproduct release
- Over 75% relative humidity promotes microbial growth
Temperature
- Heat accelerates microbial metabolic processes including odor molecules
- Bacteria thrive at temperatures between 68°F – 100°F
- Mold grows fastest at warm temperatures of 80°-90°F
Controlling humidity and temperature during clothing storage keeps microbes in check and reduces musty smells. Proper conditions can prevent a stain-free garment from becoming malodorous over time.
Conclusion
Musty odors in stored clothing arise mainly from bacteria and mold metabolizing on fabric fibers and releasing smelly volatile organic compounds. By understanding the causes, taking steps to deter microbial growth, and using odor absorption methods, clothes can be packed away without taking on that distinct musty smell. With extra moisture control and air circulation, clothes can stay fresh smelling until their next use.