To wash a woollen sweater at home, check the care label, use a gentle wool detergent, then dry it flat in the shade. Winter is here, so many of us are pulling out knitwear that has sat in a cupboard for months. This guide covers the hand wash, the machine wash and the drying step that most people get wrong.

Quick answer

  • First, read the care label. If it says hand wash only, do not use a machine.
  • Use a wool detergent or a neutral, mild one, ideally Woolmark approved.
  • Machine: use the wool cycle, or a cold wash or delicates cycle if there is none.
  • Dry flat, in the shade, away from direct sunlight.

Check the care label first

The care label tells you what the maker tested. According to the Woolmark guide to washing wool in a machine, many wool garments can go in a washing machine, but only if the care claim says machine washable. If it says hand wash only, then wash it by hand.

So, take a minute before you start. Also, a garment with no label is safer washed by hand.

How to wash a woollen sweater by hand

Hand washing is the gentlest route. The steps below follow Woolmark’s sweater care page.

  1. Fill a tub with clean, lukewarm water.
  2. Add a wool detergent, ideally one approved by Woolmark.
  3. Soak the sweater for 10 minutes.
  4. Rinse well in lukewarm water, then rinse again in cold water.

Avoid rubbing or twisting the sweater, because rough handling can damage the fibres. Instead, press the water through gently. For tips on caring for other clothes, see our winter home safety checklist while the water heats.

How to machine wash wool

A machine is fine only for garments labelled machine washable. Then follow these steps.

  1. Turn the sweater inside out, or put it in a laundry bag.
  2. Add a wool detergent, or a neutral and mild one.
  3. Choose the wool cycle. It is usually a gentle wash at 40 degrees Celsius.
  4. If your machine has no wool cycle, use a cold wash or the delicates cycle.

However, harsh detergents are not a good fit. Woolmark recommends mild, neutral ones, so skip strong stain removers on wool.

The drying step that saves your sweater

Dry knitwear flat, in the shade, away from direct sunlight. A flat surface helps it keep its shape, because hanging a wet sweater can stretch it. Meanwhile, direct sun and hot air can harm the fibres.

So, lay the sweater on a clean towel or a drying rack. Then, reshape the sleeves and body by hand. Turn it once, after a few hours, to dry both sides.

Common mistakes to avoid

  • Washing a hand wash only label in a machine.
  • Using hot water, which the guides do not recommend. Stay with lukewarm or cold water.
  • Using a regular strong detergent instead of a wool or mild one.
  • Hanging a wet sweater on a hook, then wondering why it grew longer.
  • Drying it on a terrace in harsh sun.

When to choose a professional cleaner

Some pieces are better left to experts, for example a delicate shawl or a tailored wool coat. If the label says dry clean only, follow it. Also, if you are unsure, ask the cleaner what they recommend.

For more everyday home care in the cold months, you may also like our guide to estimating a room heater electricity bill.

FAQ

How do you wash a woollen sweater at home?

Soak it in lukewarm water with a wool detergent for 10 minutes, rinse in lukewarm water, then rinse again in cold. Dry it flat in the shade.

Can I put a woollen sweater in the washing machine?

Only if the care label says machine washable. Use the wool cycle, or a cold wash or delicates cycle, with a mild detergent.

Should I dry woollens in the sun?

No. Dry knitwear flat, in the shade, away from direct sunlight. It helps keep the shape and protects the fibres.