Why indoor-dried laundry smells musty in Singapore (and how to fix it)
By Rainfresh Singapore · Updated · 4 min read
The short answer
The musty smell is mostly bacteria, not dirt. In Singapore’s ~84% average humidity, clothes dry slowly indoors, and odour-making bacteria such as Moraxella osloensis multiply on damp fabric. Dry laundry faster (higher spin, space between items, a fan or dehumidifier), don’t overdose detergent, and keep the washing machine clean and open between washes.
Why it happens here
Singapore’s mean relative humidity is about 84%, rising above 90% before sunrise and often hitting 100% during long spells of rain (Meteorological Service Singapore). The inter-monsoon months of October–November bring afternoon thunderstorms, and December is usually the wettest month. That is exactly when laundry ends up drying indoors — slowly.
A 2012 study in Applied and Environmental Microbiology traced the classic “wet dustcloth” smell to the bacterium Moraxella osloensis, which produces a compound called 4-methyl-3-hexenoic acid. It feeds on leftover sweat and skin oils, and it tolerates drying and UV well — so it survives the wash and wakes up again while clothes sit damp. A 2025 BMC Biology study saw the same pattern: washing removed odour, but it returned while clothes dried in humid air.
What actually fixes it
- Dry faster. Use your machine’s highest safe spin for the fabric, hang items with space between them, and point a fan at the rack. In Which? testing, a dehumidifier roughly halved indoor drying time.
- Aim to have clothes dry within about five hours. This is a manufacturer rule of thumb (Daikin’s research on Moraxella), not a lab standard — but the principle is solid: the shorter the damp window, the less smell.
- Don’t overdose detergent. Samsung Singapore notes that too much (or the wrong) detergent leaves residue that doesn’t rinse out and starts to smell.
- Keep the machine dry. Leave the door and detergent drawer open after each wash, wipe the door seal, and run a drum-clean cycle about monthly (Samsung, LG).
- Vinegar is not universal. Some makers suggest it for cleaning cycles; others warn acids can damage parts. Follow your machine’s manual.
Raincoats, shoes and HDB drying
- Shoes: take out the insoles, stuff with newspaper and keep them away from direct heat, which weakens glue (Nike care guide).
- Rain gear: hang it open until it is completely dry before folding it away, or it grows mildew.
- Bamboo poles: secure them in the holders and never criss-cross them — HDB treats falling items as killer litter. Wring clothes so they don’t drip on neighbours.
- Corridor racks: SCDF allows a foldable rack in the common corridor only if a 1.2 m clear escape path remains.
Sources
- Meteorological Service Singapore — Climate of Singapore
- Kubota et al. (2012), Moraxella and laundry malodour — Applied and Environmental Microbiology
- BMC Biology (2025) — odour on worn, washed and dried textiles
- Which? — drying laundry with a dehumidifier
- Daikin — Moraxella odour experiments
- Samsung Singapore — removing washing machine odour
- HDB — keeping killer litter away
- SCDF — fire safety guidelines for residential estates
- Nike — how to dry shoes
General home-care information, not professional, medical or religious advice. Sources checked 8 Oct 2026.
