Why Do Your Cloth Nappies Smell? A Wash Routine Troubleshooting Guide

You've been washing your cloth nappies the same way for weeks, everything has been fine, and then suddenly the smell hits you the second your baby wets a fresh nappy. If it's sharp enough to sting your eyes, you're not imagining it, and you're definitely not alone.

First, work out what you're actually dealing with

Not every smell is the same problem. A mild, slightly musty smell after a wash usually points to a routine that needs a small tweak. A sharp, eye watering smell, especially one that seems to appear the moment your baby wees, is ammonia, and it's worth taking seriously, since it can lead to redness and irritation on your baby's skin if left unresolved.

Where ammonia actually comes from

Ammonia develops when urine isn't being fully removed during your wash routine, or when soiled nappies sit in low airflow storage for too long. Dry pailing, storing dirty nappies in a basket with plenty of holes rather than a sealed container, is important. A closed environment is exactly the kind of place ammonia thrives in.

The most common causes, and how to fix each one

Wash routine gaps are the most frequent culprit. Run through these basics: is your load size correct (a front loader should be loosely full when loaded with dry items, around two thirds full once ), is your detergent amount matched to your load size and soiling level, and are you washing at up to 60°C? Cold washing rarely removes soiling fully over the long term, and anything below that temperature range makes ammonia far more likely to build up.

Storage airflow is the second most common cause. If your dry pail is a sealed bucket rather than something with ventilation, that's very likely contributing to the problem, regardless of how good your wash routine otherwise is.

Teething can also be a temporary trigger, since it often leads to more concentrated urine. A daily pre-wash at up to 60°C during this stage can help keep on top of it.

When you need a strip wash

If you've addressed load size, detergent, temperature and storage airflow and the smell persists, a strip wash may be needed to lift built up residue from deeper in the fabric. This is different to the old soak-in-a-bucket method many of us grew up around, which isn't recommended today. While a full bucket of water poses a drowning risk with little ones nearby, the once preferred soaking agent now consists of a different formulation, and can actually degrade the natural fibres in the modern nappy materials over extended periods.

For deeper troubleshooting

Wash routines can vary by machine, water hardness and household, so for specific detergent recommendations and step by step strip washing guidance, Clean Cloth Nappies Australia is the trusted independent resource we point our own community to. Our care and washing instructions cover the basics of what your routine should look like day to day.