Why does laundry smell better if it’s been hung up outside?

Asked by: William Peden, Norwich

Unless you wash clothes on a 90°C cycle, they will still have bacteria trapped in their fibres. The warm, damp conditions after the clothes come out of the machine will encourage growth of the bacteria, and the waste compounds they excrete will create a stale, funky smell. Hung outside, clothes generally dry much quicker, and the ultraviolet light from the Sun kills bacteria quite effectively. In spring and summer, clothes might also trap pleasant-smelling volatile organic compounds released by plants.

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