How to Wash Cashmere Without Ruining It
The wash takes ten minutes. The mistakes take two seconds.
Cashmere is the undercoat of the cashmere goat, combed out rather than shorn, and the fibers are 14 to 19 microns in diameter with a staple length of 34 to 38 millimeters. That fineness is why it feels the way it does, and it is also why it is fragile in the wash. The fibers are short, so they slip out of the yarn more easily than merino, whose staples run 60 to 100 millimeters. Short fibers plus agitation equals pilling, and agitation is what a washing machine does. The hand wash is not a ritual. It is the only wash that does not agitate the fibers enough to pill them.
The method is simple and it is the same one the care labels describe. Soak the garment in cool water with a neutral detergent made for cashmere or delicates, and let it soak for about ten minutes without rubbing or twisting. Agitate gently if you agitate at all, rinse with cool water, and press the water out by squeezing gently, never wringing. Then lay it flat to dry on a clean towel, reshaping it as needed, away from sunlight and direct heat. The whole process takes ten minutes of attention and a few hours of drying, and the sweater comes out the way it went in. Cashmere pilling has causes and fixes, and the wash is the first cause and the first fix.
The machine question, answered honestly
Can cashmere go in the washing machine? The care label decides, and if the label says hand wash only, the machine is not an option. If the label allows a machine wash, use a mesh laundry bag, a short program of no more than 30 minutes on delicate or wool at 30 degrees or colder, preferably cold, with minimal spin, and a delicate liquid detergent made for wool. Turn the sweater inside out before washing to reduce surface abrasion. The machine is a compromise, not a convenience: it saves ten minutes and costs fiber life, and the cost shows up as pilling under the arms and along the sleeves, where friction is highest.
Dry cleaning is not the best choice either, despite what the tag suggests. The harsh chemicals sap the life out of the fibers, and the process does nothing a hand wash cannot do better. Ventilate the garment after every use, and wash it every five to seven wears, not every wear. A cashmere sweater that is aired between wears and washed sparingly lasts longer than one that is washed after every outing, because every wash is a small amount of damage, and the damage accumulates. Cashmere grades are a micron number, and the micron number does not protect a sweater from a bad wash: a Grade A sweater washed wrong pills faster than a Grade C sweater washed right.
The drying mistake that ruins more sweaters than the wash
Never hang a wet cashmere sweater, and never put it in the dryer. A wet sweater is heavy, and hanging stretches it out of shape permanently, usually at the shoulders, where the hanger leaves two points that never go back. The dryer is worse: heat plus tumbling felts the fibers, and a felted sweater is a smaller, thicker sweater that no longer fits. Lay it flat on a towel, reshape it to its original measurements, and let it dry away from sunlight and direct heat. Turn it once if you remember. The drying takes hours, and the hours are the price of keeping the shape.
The pilling that does appear gets removed with a cashmere comb or a sweater stone, after washing, not before, because the pills are loose fibers and the comb lifts them without cutting the yarn. Do not pull pills off by hand, because pulling takes good fibers with the pill. And rest the sweater: the 24-hour rest rule exists because knits need a day off, and a sweater worn two days in a row pills faster than one that rests. The wash, the dry, and the rest are the whole system, and none of them is optional.
Frequently asked questions
Can I machine wash cashmere?
Only if the care label allows it. Use a mesh laundry bag, a short delicate or wool program of no more than 30 minutes at 30 degrees or colder, minimal spin, and a delicate wool detergent. Turn the sweater inside out first. Hand washing is still the safer method.
How often should I wash cashmere?
Every five to seven wears, not every wear. Ventilate the garment after every use and spot clean small marks. Every wash is a small amount of damage, and washing sparingly extends the sweater's life.
Why does my cashmere pill?
Because the fibers are short, 34 to 38 millimeters, and they slip out of the yarn under friction. Pilling is worst under the arms and along the sleeves, where friction is highest. Wash gently, turn inside out, and remove pills with a cashmere comb after washing.
Can I put cashmere in the dryer?
Never. Heat plus tumbling felts the fibers, and a felted sweater shrinks and thickens permanently. Lay it flat to dry on a towel, reshaped, away from sunlight and direct heat.