How to Wash Wool: Hand Wash, Wool Cycle and Drying Flat

Step by step

1
Check the label
Only machine-wash wool that's labeled machine washable. Everything else is hand wash or dry clean, as the label says. Laundry symbols explains the hand-wash and wool-cycle symbols.

Why: Machine-washable wool has been treated to resist felting. Untreated wool can shrink badly in a machine, even on a gentle setting.
2
Hand wash in lukewarm water
Turn the item inside out. Fill a basin with lukewarm water, about 30°C (86°F), and dissolve a small amount of mild wool detergent in it before adding the wool. Submerge it and let it soak about 10 minutes, pressing it gently rather than rubbing.

Why: Pre-dissolving detergent avoids concentrated specks, which Woolmark says can damage wool. Minimal agitation keeps the fiber scales from interlocking.
3
Or use the wool cycle
For machine-washable wool, turn it inside out and use the wool or gentle cycle, usually about 40°C (104°F), with a mild wool detergent. If your machine has no wool cycle, use a cold delicates cycle.

Why: Woolmark recommends this gentle action and a mild, neutral detergent because they prevent felting.
4
Rinse without shocking the fiber
Rinse in lukewarm water, then cool water, pressing the water through rather than swishing hard. Keep agitation to a minimum.

Why: The American Cleaning Institute advises minimal agitation in both wash and rinse for wool, because movement plus warmth is what causes felting.
5
Squeeze out water, don't wring
Gently squeeze the water out, then roll the item in a towel and press. Never wring or twist it.

Why: Wringing stretches wet wool out of shape and rubs the fibers together, which encourages felting.
6
Dry flat and reshaped, away from heat
Lay knitwear flat on a pale, lint-free towel and reshape it to its original size. Woven pieces like coats can hang. Keep it away from radiators, heaters and direct sun. Tumble dry only if the label allows it, on the wool or low setting.

Why: Wet knitwear is heavy and stretches if hung. Heat and strong sun can damage and discolor wool.

What wool is, and why it shrinks

Wool is an animal protein fiber, and under a microscope each fiber is covered in overlapping scales. When wool is wet, warm and agitated, especially in alkaline conditions, those scales open, catch on each other and lock together. That's felting, and it shrinks and thickens a sweater permanently. Every washing rule for wool exists to avoid that combination of heat, movement and alkali.

Wool's chemistry also rules out several common laundry products. Georgia extension notes that protein fibers are damaged by alkaline soaps and high temperatures. Chlorine bleach yellows and damages wool permanently. Enzyme ("bio") detergents are made to break down protein, and Woolmark advises against them and against heavy-duty detergents. The good news is that wool is naturally resistant to odor and stains, so it needs washing far less often than cotton: air it out between wears.

How to spot clean a wool rug

A wool rug needs the same gentle chemistry as a sweater, but with as little water as possible:

Blot up spills right away with a white cloth. Don't scrub, which damages the pile.
Pretest any cleaning solution on a hidden spot. The Carpet and Rug Institute stresses this, especially on wool.
Mix a very dilute detergent solution, about ¼ teaspoon of mild liquid dish soap in 1 cup of lukewarm water. Apply it sparingly with a cloth, working from the edge of the spot toward the center, and blot.
Blot-rinse with plain water so no detergent residue is left; wool is sensitive to alkaline residue.
Press dry with white towels and let the area dry fully.

Skip chlorine bleach, oxygen bleach, ammonia and enzyme cleaners on wool rugs: each can damage the fiber or the dyes. Hand-knotted, Oriental and heirloom rugs should go to a rug specialist. See area rugs for routine care.

By situation

Wool sweaters

Hand wash, or use the wool cycle only if labeled, and always dry flat and reshaped. Between wears, air them out instead of washing.

Wool blankets

Woolmark suggests washing wool blankets about every three months. Follow the label: if it allows machine washing, use the wool cycle; if not, or if the blanket is too large to handle gently, use a professional cleaner.

Wool coats and tailored items

These are usually labeled dry clean only, because of how they're constructed. Air them between cleanings, and follow the label.

Stains on wool

Blot, then sponge with cool water and a little mild wool detergent, and rinse. Avoid enzyme stain removers, chlorine and oxygen bleach, and undiluted ammonia. For blood, use cold water only; see blood on clothes. Take valuable items to a professional.

Wool that shrank

Felting can't be reversed, because the scales have locked together. Prevention is the only real fix: cool water, mild detergent and minimal agitation.

What not to do

Don't use chlorine bleach on wool. It yellows and damages wool permanently.
Don't use oxygen bleach, enzyme ("bio") or heavy-duty detergents. Woolmark advises against all of them for wool. ACI describes oxygen bleach as safe for all washable fabrics, so the sources conflict; follow the wool label.
Don't use hot water, agitate or wring wool. Heat and movement make the fiber scales lock together, which felts and shrinks the item.
Don't dry wool on a radiator or in strong sun. Uneven heat can damage and discolor it.
Don't pour powder detergent straight onto wool. Woolmark warns that concentrated specks can cause holes; dissolve it in the water first.

Other methods that work

Airing out instead of washing

Wool resists odors and stains naturally, so hanging it in fresh air between wears often removes light smells without a wash.

Caution: Keep it out of direct sun while airing, which can fade and weaken it.

Professional dry cleaning

For dry-clean-only wool, tailored coats, large blankets and heirloom rugs, a professional cleaner avoids the risk of felting.

Caution: Tell the cleaner about stains and what caused them.

Stain still there?

My wool sweater shrank

It felted from heat or agitation, and that's permanent. Next time, hand wash in lukewarm water, don't wring, and dry flat.

Wool went yellow

If chlorine bleach caused it, it's permanent. Use only mild wool detergent and no bleach from now on.

A sweater stretched out of shape

It was hung or wrung while wet. While it's damp, reshape it on a flat surface, and always dry knitwear flat.

Questions

Can you put wool in the washing machine?

Only if the label says machine washable. Use the wool or gentle cycle, usually about 40°C (104°F), with a mild wool detergent.

What water temperature should I use for wool?

Lukewarm, about 30°C (86°F), for hand washing. Avoid hot water, which helps the fibers felt.

Can I use regular detergent on wool?

It's better not to. Woolmark advises a mild, neutral detergent and no enzyme or heavy-duty products, which can damage the protein fiber.

How do you spot clean a wool rug?

Blot, pretest, then dab on a very dilute dish soap solution (about ¼ teaspoon per cup of water), blot-rinse with plain water and press dry. Avoid bleach, ammonia and enzyme cleaners.

How often should you wash wool?

Rarely. Wool resists odor and stains, so airing between wears is often enough. Woolmark suggests about every three months for blankets.

More laundry guides

Sources

How to wash wool, The Woolmark Company (wool industry body)
How to dry wool, The Woolmark Company (wool industry body)
Best detergent to use when washing wool, The Woolmark Company (wool industry body)
Using Bleach in the Laundry, American Cleaning Institute
Laundering Problems and Solutions, American Cleaning Institute
Fiber Types, University of Georgia Cooperative Extension (Textiles)
Understand Your Fibers, University of Georgia Cooperative Extension
Spot Solver: Feces (general spot-removal steps and solution recipes), The Carpet and Rug Institute

Last updated October 26, 2026. Methods are drawn from the sources above; how we research and check our guides.