Key points
- Hand-wash cashmere and fine wool in cool water with a wool-specific detergent; never wring, never tumble-dry.
- Dry flat on a towel, reshaped; never hang a knit — wet or dry.
- Fold and store clean with cedar or lavender; moths eat dirty knitwear first.
- De-pill with a cashmere comb, not a razor; a little pilling early on is normal.
- Wash less: airing after wear does most of the work.
A fully-fashioned cashmere sweater from a Scottish or Italian mill is designed to last twenty years. Most do not, and the reason is almost always care: a hot wash, a wire hanger, a summer in an open wardrobe. The good news is that fine knitwear is not delicate so much as particular. Follow the routine below and your knitwear will outlast the rest of your wardrobe.
First rule: wash less
Wool and cashmere are self-cleaning to a surprising degree. The fibre's scaly surface and natural moisture regulation resist odour, and a sweater that is aired for a day after wearing — laid flat or draped over a chair, not hung — is usually ready to wear again. Wash after roughly five to ten wears, or when there is a visible mark. Every wash removes a little fibre and a little life; airing costs nothing.
How to hand-wash cashmere and fine wool
- Fill a basin with cool water (20–30°C). Hot water and sudden temperature changes are what felt and shrink wool.
- Add a wool-specific detergent — one without enzymes, which digest protein fibre. Baby shampoo works in an emergency. Never use ordinary biological detergent or fabric softener.
- Turn the sweater inside out and submerge it. Squeeze gently to move water through the fabric. Do not rub, twist or wring. Leave it for ten minutes; do not soak for hours.
- Rinse in cool water of the same temperature until the water runs clear, supporting the garment's weight so it does not stretch.
- Press out water by squeezing, then lay the sweater on a dry towel, roll the towel up and press to absorb more. Never wring.
Can you use a washing machine?
Modern machines with a genuine wool cycle (30°C, minimal agitation, no or very slow spin) will wash most cashmere and merino safely, provided you use a mesh bag and wool detergent. Superwash-treated merino is designed for it. But the margin for error is small — a mis-set cycle destroys a sweater in forty minutes — and the manufacturer's label is the final word. Most houses in this index recommend hand-washing; several accept a wool cycle. When in doubt, hand-wash.
Dry cleaning: helpful or harmful?
Dry cleaning solvents remove oils and can leave cashmere feeling dry and flat, and repeated dry cleaning shortens a sweater's life. It is the right choice for structured or embellished pieces, vicuña, and stains that water will not shift; for a plain cashmere or merino sweater, a careful hand-wash is gentler and produces a softer result. If you do dry clean, use a specialist who knows knitwear and ask for a gentle process.
Drying and reshaping
Lay the sweater flat on a dry towel or a mesh drying rack, away from direct sun and radiators, and reshape it gently with your hands: pull the body to its correct length, square the shoulders, straighten the sleeves, pat the ribs back into shape. Turn it once during drying. It will take a day or so. Never hang a wet knit — the weight of the water will stretch it permanently — and never tumble-dry, which felts the fibre irreversibly.
Once dry, a light steam (a steamer or an iron on the wool setting held just above the fabric) will refresh the surface and relax any creases.
Storing knitwear
Fold, never hang. Hanging stretches the shoulders and lengthens the body, and the marks left by a hanger at the shoulder are permanent. Fold sweaters and store them flat in a drawer, on a shelf, or in a breathable cotton bag. Do not seal them in plastic for long periods; the fibre needs to breathe.
At the end of the season, wash everything before storing — moths are attracted to skin oils and food traces, not to clean wool — and store it in a closed drawer or box with cedar blocks or lavender sachets. Cedar loses its scent within a year; sand the surface lightly to refresh it.
Moths
The clothes moth (Tineola bisselliella) lays eggs on protein fibre, and the larvae eat holes in it, preferring dark, undisturbed places and soiled garments. Prevention: store clean, store closed, disturb stored knitwear every few months, and keep wardrobes dry. If you find a hole or a larva: freeze the affected garment in a sealed bag for 48 hours (which kills eggs), then wash it; vacuum the drawer or wardrobe thoroughly; and use pheromone traps to monitor. Small holes in cashmere can be invisibly mended by a specialist reknitter, and several houses in this index offer repair services.
Pilling
Pilling — small balls of fibre where the fabric rubs, typically under the arms and where bags or seatbelts cross — is normal in the first weeks of a cashmere sweater's life, as loose fibre ends work their way out. It reduces after the first few washes. Remove pills with a cashmere comb or a fine sweater comb, laying the garment flat and combing gently in one direction. Electric de-pillers are effective but can cut healthy fibre if pressed hard. Never use a razor. A sweater that pills heavily across its whole surface within a few wears was made from short-fibre yarn; see the cashmere grading guide.
Notes by fibre
- Cashmere: the routine above. It softens with washing; a well-made sweater is at its best after a year.
- Merino: more forgiving; a wool cycle is usually safe. Superwash merino can be machine-washed routinely.
- Alpaca: stretches when wet more than wool because it lacks elasticity. Support its weight at every stage and reshape carefully.
- Vicuña: professional cleaning only, and rarely.
- Lambswool and Shetland: robust; hand-wash and dry flat. Shetland softens noticeably after the first two or three washes.
- Mohair: hand-wash, never rub; shake gently when dry to restore the halo.
- Cotton: gentle machine wash cool, reshape and dry flat; fine-gauge cotton stretches if hung.
The whole routine in one line: air after wearing, hand-wash cool every five to ten wears with wool detergent, dry flat and reshaped, fold with cedar, comb pills gently. That is all a twenty-year sweater needs.
Frequently asked questions
Can you machine-wash cashmere?
Many cashmere sweaters survive a machine wool cycle at 30°C in a mesh bag with wool detergent and no spin, but hand-washing is safer and gentler. Never use a normal cycle, hot water or a tumble dryer, which felt and shrink the fibre. Most luxury houses recommend hand-washing or dry cleaning.
How often should you wash a cashmere sweater?
Wash cashmere after roughly five to ten wears, or when it is visibly soiled or smells. Between wears, air it for a day before folding. Over-washing wears fibre out; under-washing invites moths, which are attracted to skin oils and food traces.
How do you get rid of pilling on a sweater?
Lay the sweater flat and gently comb the pills away with a cashmere comb or a fine-toothed sweater comb, working in one direction. Electric de-pillers work but can cut healthy fibre if pressed hard. Never use a razor. Pilling reduces after the first few washes as loose fibre ends are removed.
Should you hang or fold knitwear?
Always fold knitwear. Hanging stretches the shoulders and lengthens the body under its own weight, and the marks are permanent. Fold sweaters and store them flat in a drawer or on a shelf, ideally with cedar or lavender to deter moths.
How do you protect cashmere from moths?
Store knitwear clean — moth larvae are drawn to skin oils and food traces — in a closed drawer, box or breathable bag, with cedar blocks or lavender sachets. Freeze a suspect garment for 48 hours to kill eggs. Check stored knitwear every few months and refresh cedar by sanding it lightly.