Wool resists odour naturally and releases it when aired. Over-washing is the main cause of felting, shrinkage and pilling.
The short answer
5–10 wears
When to wash sooner
Wash it now if
- a smell that survives a night of airing
- a spill
- the end of the season, before storage
What to do between washes
Air overnight near an open window. Wool genuinely resets this way — it is not a compromise.
How to wash them
Wool cycle at 20°C with a non-biological wool wash, low spin, dried flat. Never hang wet knitwear.