How to Wash a Wool Sweater Without Shrinking It
By TaVare · updated 2026-07-27
Wool tolerates more than most people think. A sweater does not shrink from heat itself, but from the combination of movement, temperature shock and the wrong detergent – that is when the fibres lock together and felt. Wash it gently, at an even temperature and with the right product, and a wool garment keeps its shape. Wool is also self-cleaning, so airing it is often enough.
Why wool shrinks and felts
Wool fibre has tiny scales on its surface. When exposed to movement, sudden temperature change and alkaline (ordinary) detergent, the scales lock into each other and the garment felts and shrinks. So it is not heat alone – a wool garment lying still in lukewarm water will not shrink. Rubbing, temperature shock and the wrong product are the culprits.
Air it rather than wash it
Wool is self-cleaning and resists odour. Often it is enough to hang the sweater to air after wear and treat individual marks straight away. Then you wash it less often, and the garment stays nice far longer.
Hand washing – step by step
Hand washing is safest for wool. The key is to be gentle and keep the temperature even.
- Use lukewarm water and a wool detergent without enzymes and without fabric softener.
- Soak the sweater and gently squeeze the water through – do not rub, wring or stretch.
- Rinse in water at the same temperature, as temperature shock felts the wool.
- Squeeze – do not wring – out the water, and roll the sweater in a towel to press out the rest.
Machine washing on a wool programme
If the care label says the garment is machine safe, use a wool or hand-wash programme with a low spin, a wool detergent and ideally a mesh bag. The same principles apply: even, low temperature and as little movement as possible.
Always dry flat
Never hang a wet wool sweater – the weight stretches it out of shape. Lay it flat on a towel, reshape it to the right size while damp, and let it dry away from direct heat and sun.
Shrunk it anyway? And when to have it cleaned
If the sweater has shrunk, soak it in lukewarm water with a little hair conditioner to soften the fibres, and gently reshape it. That often restores the size, but not always the original loft. For a valuable, structured or inherited piece – such as a bunad – leave it to professionals. We clean gently according to the fabric and care label, and you see the price before you order.
Frequently asked questions
Does wool shrink from hot water?+
Not from heat alone. It is the combination of movement, temperature shock and alkaline detergent that felts wool. An even temperature and gentle handling protect it.
How often should I wash my wool sweater?+
Rarely. Wool is self-cleaning – air it, treat individual marks and wash only when needed.
Can I use fabric softener on wool?+
No. Use a wool detergent without enzymes and without softener, made to protect the fibres.
Can I save a shrunken wool sweater?+
Often partly. Soak in lukewarm water with a little hair conditioner and reshape the garment. Felting is unfortunately partly permanent.
Ready to fix it?