How to wash a wool sweater: check the label, wash gently, dry flat

By Cleaning Notes

Start with the sweater’s care label. If it permits hand washing, use lukewarm water and a mild wool detergent, handle the knit gently, rinse and press out the water without wringing. If it permits machine washing, use the specified temperature and a wool cycle. After either method, dry the sweater flat unless its label explicitly allows tumble drying. See Woolmark’s sweater-washing guidance and drying instructions.

Choose the method before getting it wet

Care label	What to do
Hand wash only	Wash in a basin or sink; don’t substitute a machine’s delicate cycle.
Machine washable	Follow the label’s temperature and cycle instructions; use the washer’s wool setting where available.
Dry clean only or do not wash	Don’t use either home-washing method below. Follow the professional-care instructions.
Missing or unreadable	Ask the manufacturer or a professional cleaner before washing rather than guessing.

Woolmark explains that a do not wash label can indicate sensitivity to wet treatment, while machine-washable wool requires reduced mechanical action. A sweater being wool—or Merino wool—does not by itself tell you which method is suitable. Check the care instructions for the whole garment.

Choose a wool-safe detergent

Use a neutral, mild detergent labeled as suitable for wool, at the dose specified for your washing method. Don’t assume an ordinary laundry detergent is suitable just because it is described as gentle.

Woolmark advises avoiding heavy-duty detergents, “bio” detergents containing enzymes, and detergents containing bleach. Do not use chlorine or oxygen bleach on wool. If using a suitable powder, dissolve it before it contacts the sweater. See Woolmark’s detergent guidance, and follow your chosen detergent’s washing instructions.

How to hand-wash the sweater

For a sweater whose label permits hand washing:

1. Prepare the basin. Fill a clean sink or basin with lukewarm water—about 30°C / 86°F, unless the care label specifies otherwise. Mix in the wool detergent.
2. Turn the sweater inside out and submerge it. Move it gently through the water to wet it evenly. Don’t rub, scrub or pull the knit.
3. Soak for about 10 minutes. Follow any more specific garment or detergent instructions.
4. Rinse thoroughly. Woolmark’s routine uses lukewarm water first, followed by a final cold-water rinse.
5. Press out excess water carefully. Don’t twist or wring the sweater. Move it to the flat-drying surface below, supporting the wet garment rather than letting it dangle.

The temperature, soak and rinse sequence come from Woolmark’s hand-washing guide; its care-label guide specifies gentle handling and pressing rather than wringing.

How to machine-wash it

Only use this method when the sweater’s label permits machine washing.

• Turn the sweater inside out; a laundry bag is another option.
• Add wool-safe detergent at the labeled dose.
• Select the wool cycle and a temperature consistent with the garment label. If there is no wool cycle, Woolmark recommends a cold-water or delicates cycle; check your washer’s instructions to choose a suitable setting.
• Keep the load small. For garments labeled for a very mild 30°C or 40°C wash, Woolmark says the drum should be no more than one-third full.
• After washing, lay the sweater flat to dry.

See Woolmark’s machine-washing steps and load guidance.

Dry flat to preserve the shape

Lay the sweater on a clean, lint-free white or pale-colored towel, or a mesh drying surface that supports the whole garment. Gently ease it back into its original shape and smooth out folds without stretching it.

Let it air-dry away from direct sunlight and heat. Don’t hang a wet wool sweater on a hanger or clothesline: the weight of the water can stretch the knit. Don’t drape it over a radiator to speed drying. Use a tumble dryer only if the sweater’s care label explicitly permits it, following the specified setting. These precautions follow Woolmark’s drying guidance.

Give the sweater time to dry fully before folding it away; don’t use extra heat to rush the final damp areas.