How to wash merino wool sweaters, base layers and socks

Step by step: how to wash merino wool sweaters, base layers and socks

1. 1

   Air it first and wash only when needed

   Merino resists odor, so many pieces only need airing between wears. Hang a sweater or lay out socks overnight in fresh air and they are often ready to wear again. Wash when it smells, looks soiled or after several wears.

2. 2

   Read the care label

   Look for machine wash, hand wash or dry clean only. Machine washable merino is treated so it will not shrink in a wool cycle; untreated wool can felt and shrink badly if it is agitated in warm water. If the label says dry clean only, do not wash it at home.

3. 3

   Turn it inside out and bag it

   Turn sweaters, base layers and socks inside out to reduce pilling and protect the outer face. Put sweaters and thin layers in a mesh laundry bag, and wash wool with other light items, not with jeans or towels.

4. 4

   Machine wash on the wool or cold delicates cycle

   Choose the wool cycle if your washer has one. If not, use a cold delicates or gentle cycle with a low spin. Add a measured dose of wool detergent; skip bleach and fabric softener.

5. 5

   Or hand wash in lukewarm water

   For hand wash only pieces, fill a basin with lukewarm water, about 86°F, and dissolve a little wool detergent. Submerge the garment, press it gently and let it soak for about 10 minutes. Do not rub, twist or scrub.

6. 6

   Rinse lukewarm, then cold

   Drain and rinse in lukewarm water first, then in cold, pressing the water through the knit. Sudden swings from hot to cold can contribute to felting, so keep the first rinse at the same temperature as the wash.

7. 7

   Roll it in a towel to remove water

   Never wring merino. Lay it flat on a clean towel, roll the towel up with the garment inside, and press down to squeeze out water. Repeat with a dry towel if it is still dripping.

8. 8

   Dry flat and reshape

   Lay sweaters flat on a dry light-colored towel or a mesh rack, ease them back to their original size and shape, and let them air dry away from radiators and direct sun. Turn them over once to speed drying. Socks and thin base layers can be dried flat or draped over a rack.

Can you put merino wool in the washing machine?

Yes, if the care label says machine wash: use the wool cycle, or cold delicates if there is no wool cycle, with a mild detergent. If the label says hand wash or dry clean only, follow it.

The Woolmark Company says garments with a machine-wash care claim can be washed many times without shrinking, on the wool setting (usually gentle action at 40°C, about 104°F), or on a cold or delicates cycle if your washer has no wool program. For hand wash pieces, it recommends turning the garment inside out, washing in lukewarm water around 30°C (86°F) with a mild detergent, soaking about 10 minutes, then rinsing first in lukewarm and then in cold water.

Tide cautions that most wool garments are not designed for machine washing, so the label comes first. When machine washing is allowed, it recommends a gentle cycle, cold water and a mesh bag, then pressing out water rather than wringing and laying the garment flat to dry.

How to wash wool sweaters, socks and base layers

Every merino item gets the same gentle treatment; what changes is how often you wash it and how you dry it.

Woolmark’s advice on wool socks is to air them overnight between wears, and when they do need a wash, to turn them inside out and use the wool setting or a cold delicates cycle with a mild detergent.

How to dry merino without shrinking or stretching it

Dry knitted merino flat, away from heat, unless the label says it can be tumble dried. Heat and hanging are what ruin sweaters, not the wash.

• Woolmark recommends drying knitwear flat on a pale, lint-free towel, kneading it gently back into shape, and avoiding direct sunlight, heaters and radiators. Hanging a wet sweater lets the weight of the water stretch it longer.
• Tumble dry only if the care label says so, and then on a low or wool setting.
• Woven wool, like trousers and jackets, can dry on a hanger out of direct sun.
• Do not use chlorine bleach on wool. Clorox says to always avoid bleaching wool, silk, mohair, leather and spandex.
• Washing a mixed load of delicates by hand? Our guide to washing clothes by hand walks through the basin method.

Mistakes to avoid

• Washing untreated or hand wash only wool on a warm, normal cycle, which felts and shrinks it.
• Wringing or twisting wet wool, which stretches and distorts the knit.
• Hanging a wet sweater, which pulls it longer as it dries.
• Drying on a radiator or in direct sun, which can yellow the fiber and shrink the part touching the heat.
• Using chlorine bleach or an enzyme stain spray on wool.
• Washing merino with towels and jeans, which roughs up the surface and adds lint.