Cashmere is easier to wash at home than almost anyone believes, and repeated dry cleaning is worse for it than careful hand washing. The solvents are harsh on a fibre this fine.
Here is the method.
What ruins cashmere
Three things, in order of damage.
Heat. The single biggest cause. Hot water and tumble drying make the scales on the fibre open and lock together, which is felting, and felting is permanent. There is no undoing it.
Agitation. Rubbing, wringing and machine spinning do the same thing more slowly. Cashmere should be moved through water, not worked in it.
The wrong detergent. Ordinary biological detergent contains enzymes designed to break down protein. Cashmere is a protein. Over time it will thin the fibre.
The method
- Fill a basin with cool water. Cool, not warm — if it feels warm on your wrist it is too hot.
- Add a small amount of detergent made for wool, or a plain baby shampoo. Both are gentle and pH-appropriate. Swirl to dissolve before the jumper goes in.
- Submerge and leave it. Press it under and let it sit for up to thirty minutes. Do not rub, twist or scrub. If there is a mark, press the detergent through that spot with your fingers.
- Rinse in water of the same temperature. A sudden change in temperature causes shrinkage on its own. Rinse until the water runs clear.
- Press the water out, never wring. Gather it into a ball and squeeze gently.
- Roll it in a towel. Lay it flat on a dry towel, roll the two together, and press. This removes far more water than squeezing does.
- Dry flat, in shape. Lay it on a fresh dry towel away from radiators and direct sun, and reshape it with your hands to the dimensions it should be. Never hang it — the weight of the water will pull the shoulders down permanently.
Give it a day. Turn it once.
Can you machine wash it
Sometimes, with care. If your machine has a genuine wool or hand-wash cycle that keeps the temperature at or below 30 degrees and the spin low, put the jumper in a mesh bag with wool detergent and use it.
The risk is not the wash, it is the spin. If you can reduce the spin speed, do.
How often
Less often than you think. Cashmere does not hold odour the way cotton does, and every wash is a small amount of wear.
Air it overnight between wears, spot-clean marks, and wash it every four or five wears, or when it genuinely needs it. Always wash it before storing for the summer — moths are attracted to the traces we leave on fabric, not to clean wool itself.
After washing
A freshly washed cashmere jumper often looks slightly fluffy. That is normal. It will settle.
If it has pilled, deal with that separately — how to remove bobbles from knitwear covers it, and pilling is a fibre-length issue rather than a washing mistake.
For storage, fold rather than hang, and keep it somewhere dry — how to store knitwear covers the rest.
Buying it in the first place
Not all cashmere is equal, and the label alone does not tell you. Ply, fibre length and knit density matter more than the percentage. What makes a knit good quality covers what to check before buying, which is the part that decides how well the jumper survives everything above.