How To · Fashion · Care
How to Wash and Care for Wool and Knit Sweaters
A quality sweater can outlast trends if you treat it right. Learn the specific moves that prevent pilling, stretching, and that dreaded felting.
5 min read · IrisWool and knit sweaters are investments in your rotation, not disposable layers. The difference between a sweater that pills into oblivion and one that holds its shape for a decade comes down to one thing: how you wash it. Forget the dryer. Ignore the aggressive spin cycle. This is about patience and cold water.
The good news: proper sweater care takes barely any time and costs nothing. You're already buying the detergent. What changes is method—and once you nail it, you'll never stress about a cashmere blend again.
Wool doesn't need hot water to get clean. Cold water, a gentle detergent, and your hands are all you need.
Step one · 2 minutes
Fill a basin with cold water and mild detergent
Use a sink, bucket, or bathtub—whatever fits your sweater comfortably. Fill it with cool water (not warm, not hot). Add a small squirt of wool-specific detergent or a gentle, pH-neutral soap. Woolite, The Laundress, or even a drop of baby shampoo work. Stir the water gently so the soap disperses evenly. The water should feel slightly slippery, not soapy.
Avoid regular laundry detergent—it's too harsh and will strip the natural oils that keep wool soft.
Step two · 3 minutes
Submerge and soak without agitation
Fold your sweater loosely and place it in the water. Let it sit for 5–10 minutes. Do not scrub, wring, or agitate. The soak does the work. If there are visible stains or problem areas, gently press the soapy water into the fabric with your fingers—never rub. Think of it as coaxing dirt out, not beating it out.
If your sweater smells but isn't visibly dirty, a 10-minute soak alone can refresh it without full washing.
Step three · 2 minutes
Rinse in fresh cold water
Drain the soapy water. Refill the basin with clean, cold water. Gently lift the sweater and submerge it again. Swish it softly side to side—no wringing. Drain and repeat with fresh water until the water runs clear and you feel no soap residue. This usually takes 2–3 rinses. Patience here prevents stiffness later.
If water still looks cloudy after the third rinse, do one more. Leftover soap makes sweaters feel scratchy.
Step four · 2 minutes
Remove excess water without wringing
Gently lift the sweater from the water. Lightly squeeze sections of the fabric—don't twist or wring. Lay the sweater flat on a clean, dry towel. Roll the towel up with the sweater inside to absorb more water. Unroll it. The sweater should feel damp, not dripping. If it's still heavy, repeat with a second dry towel.
Never hang a wet wool sweater—gravity will stretch it out of shape permanently.
Step five · 3 minutes
Lay flat to dry on a clean surface
Lay the damp sweater flat on a clean, dry towel or drying rack. Smooth it gently into shape—check the width, length, and sleeve position. Place it somewhere with good air circulation, away from direct heat or sunlight. A guest bedroom, laundry room, or shaded porch works. Flip it once halfway through drying to ensure even moisture loss. Drying takes 12–24 hours depending on thickness and humidity.
A sweater drying rack is a small investment that pays off—it keeps air flowing underneath and prevents moisture pooling.
Step six · Ongoing
Store properly to prevent damage
Once fully dry, fold your sweater and store it flat in a drawer or shelf. Hanging stretches the shoulders and neckline over time. Use cedar blocks or lavender sachets to deter moths—wool is protein, and moths love it. Keep sweaters away from direct light, which can fade colors. In off-season, store in a breathable cotton bag, not plastic, which traps moisture.
If pilling appears, use a sweater stone or fabric comb gently—never pick at pills with your fingers, as this can damage the fibers.
How to know it works.
A properly cared-for sweater emerges from washing softer, not stiffer. The color stays true. The shape holds. Over time, you'll notice your sweaters last years instead of seasons—and they feel better each time you wear them.
Questions at the mirror.
Can I machine wash wool on a delicate cycle?
Some modern wools are machine-washable, but hand-washing gives you total control and is gentler. If you use a machine, use a mesh bag, delicate cycle, cold water, and wool detergent—then lay flat to dry. Hand-washing takes the same time and is more reliable.
What if my sweater already shrank?
Wet wool is more pliable. Soak it in cool water with a bit of hair conditioner or glycerin, then gently stretch it back to shape while damp and lay flat to dry. It won't fully recover, but this can help. Prevention is easier than repair.
How often should I actually wash a sweater?
Every 3–4 wears, or when it smells. Wool is naturally antimicrobial and doesn't hold odor like cotton. A simple soak without full washing can refresh it. Overwashing, even gently, breaks down fibers over time.
Is cashmere different from regular wool?
Cashmere is wool, just finer and more delicate. Use the same method but be even gentler during the soak—don't agitate at all. Some people use cashmere-specific detergent, which is slightly gentler, but regular wool detergent works fine.