Can you wash wool?

Wool fibres are covered in microscopic scales. Heat and agitation make those scales interlock and ratchet together, and once locked they never release — that is felting, and it is why a jumper comes out of a hot wash child-sized. Water on its own does not do this. Wash cold, move the garment as little as possible, and use a wool detergent; ordinary biological powder attacks the protein fibre in the same way it attacks silk. Never hang wet wool, because the weight of the water stretches it out of shape permanently.

How to do it properly

1. Cold water and wool detergent. Machine wool cycles are usually safe if genuinely cold.
2. Squeeze gently rather than rubbing or twisting.
3. Roll in a towel to press the water out.
4. Dry flat, reshaped by hand while damp. Never hang it and never tumble dry it.

What goes wrong

• Hot water plus agitation felts the garment irreversibly.
• Hanging wet wool stretches the shoulders and body out of shape.
• Biological detergent digests the protein fibre.

Other "can you wash" questions

• Can you wash pillows? It depends — Down and polyester pillows wash fine. Memory foam and latex must never go in the machine.
• Can you wash sneakers in the washing machine? It depends — Canvas and synthetic trainers survive a cold gentle cycle. Leather and suede do not.
• Can you wash memory foam? No — No. Memory foam disintegrates in a washing machine and cannot be dried through.
• Can you wash a weighted blanket? It depends — Usually yes, but check the weight — most domestic machines top out around 7 kg dry.
• Can you wash silk? It depends — Hand wash cold with a pH-neutral detergent. Never use biological powder or hot water.
• Can you wash stuffed animals? It depends — Most wash fine in a pillowcase on cold gentle. Anything with electronics or glued parts does not.
• Can you wash a down jacket? Yes — Yes, and you should — but it must be tumble dried with dryer balls or the down stays clumped.