Few wardrobe tasks cause as much hesitation as washing a wool jumper for the first time. One wrong temperature setting and a favourite knit can emerge shrunken, stiff or felted. Yet wool is far more resilient than its reputation suggests, and with the right approach, washing wool knitwear at home is simple and safe.
Good quality wool garments can last decades when they are looked after carefully, so it is worth learning the correct method. This guide explains how to hand wash and machine wash wool knitwear, why temperature and agitation matter, and how to keep jumpers looking their best for years to come.
Why Wool Knitwear Needs Special Care
Wool is a natural, renewable and biodegradable fibre, and merino wool in particular is one of the most versatile and resilient fibres available. Unlike synthetic materials, wool has a complex structure that responds to heat and friction. If it is washed too hot, rubbed too hard or agitated too vigorously, the fibres can shrink or felt, which ruins the softness and shape of the garment.
The good news is that these problems are almost entirely preventable. By following a few simple rules around temperature, detergent and handling, you can keep your wool knitwear in excellent condition without needing to rely on a dry cleaner.
How to Hand Wash Wool Knitwear
Gentle hand washing in cold water is probably the best way to care for wool jumpers. It avoids the mechanical action of a washing machine entirely and gives you full control over how the garment is handled. Hand washing takes a little time, but it is the most reliable way to protect a delicate knit.
Turn the garment inside out
Before the knitwear touches the water, turn it inside out. This protects the outer surface of the fabric and reduces friction on the side of the garment that is most visible when you wear it.
Prepare lukewarm water and wool detergent
Fill a clean basin or sink with lukewarm water and add a wool detergent, preferably a Woolmark-approved detergent. A gentle laundry detergent designed for silk and wool, such as Persil Silk & Wool, is also a suitable option. Follow the dosage instructions on the label rather than guessing.
Soak the knitwear and treat dirty spots
Place the knitwear into the water and make sure it is completely covered. If there are any dirty marks, gently rub a spot of wool wash into those areas and then leave the garment to soak. This gives the detergent time to lift dirt without you having to scrub at the fabric.
Move gently and never rub
Very gently move the item through the water, but do not rub or agitate it. Over agitation and rubbing can cause the wool to felt, which turns a soft jumper into a dense, matted fabric. Lift the garment out carefully and support its weight, because wet wool is fragile and should never be roughly twisted or wrung.
How to Machine Wash Wool Knitwear
Machine washing wool is possible, and many modern washing machines include a dedicated wool setting that mimics a gentle hand wash. That said, some wool garments carry a "do not machine wash" label, so always check the care label before deciding. If the label advises against machine washing, hand washing is the safer choice. For knitwear that can go in the machine, these steps will help.
Wait, I used "That said" which I wanted to avoid. Let me change to "However, some wool garments carry..." I'll fix that in the final.Turn inside out or use a laundry bag
Turn your wool sweater inside out, or place it in a laundry bag, before putting it in the machine. This protects the surface of the knit from friction against other items in the drum during the cycle.
Add a wool detergent
Add a wool detergent, preferably a Woolmark-approved detergent, to the machine. A gentle laundry detergent designed for silk and wool also works well. Measure it according to the instructions on the bottle and avoid using more than recommended.
Choose the wool or gentle cycle
Set your machine to the wool setting, or the gentle cycle if your machine does not have a dedicated wool programme. Always wash at 30°C or lower, because washing wool at a higher temperature risks shrinking the garment.
Why 30°C Is the Maximum Temperature for Wool
Temperature is the most common cause of ruined knitwear. The rule is simple: always wash wool at 30°C or lower. Cold water is the gentlest option for hand washing, and 30°C is the maximum recommended for machine washing. If your machine's temperature settings are not perfectly accurate, err on the side of cooler water to protect the fibres from heat damage.
Handling Wet Wool Knitwear
Wet wool behaves very differently from dry wool. It becomes heavy, stretches easily and is much more vulnerable to damage. When you lift a washed garment out of the basin or the washing machine, support its weight with both hands and avoid wringing or twisting it. Rough handling at this stage can cause the wool to felt just as quickly as a hot wash can.
Understanding the Care Label
It is common to see "do not machine wash" on wool jumpers, and hand washing every knit piece can feel time-consuming. When the care label allows it, the machine washing method described above is a practical alternative that many people use with good results. However, the care label is the final authority on how a garment should be treated. When in doubt, gentle hand washing in cold water is the most reliable way to avoid damage.
How Often Should You Wash Wool Knitwear?
Wool does not need to be washed after every wear. In fact, many people wear a wool jumper three or four times before deciding it needs a wash. Washing less frequently reduces wear on the fibres and means less time spent on delicate laundry. For small marks, treating the spot with a little wool wash is often enough to refresh the garment between full washes, which is kinder to the wool and to your schedule.
Wool Wash Do's and Don'ts
If you remember nothing else, remember these simple rules for washing wool knitwear.
- Do wash wool at 30°C or lower.
- Do use a wool detergent, preferably a Woolmark-approved detergent.
- Do turn the garment inside out or place it in a laundry bag.
- Do use the wool setting or gentle cycle when machine washing.
- Don't wash at a higher temperature, as this risks shrinking the garment.
- Don't rub, scrub or over agitate, as this can cause the wool to felt.
Hand Washing vs Machine Washing Wool Knitwear
Both methods work well when done correctly. The right choice depends on the care label, your washing machine and how much time you have available.
| Hand washing | Machine washing |
|---|---|
| Cold or lukewarm water | Wool setting or gentle cycle |
| Turn the garment inside out | Turn inside out or use a laundry bag |
| Add a wool detergent | Add a Woolmark-approved wool detergent |
| Let the knitwear soak | Wash at 30°C or lower |
| Move gently, never rub | Higher temperatures risk shrinking |
Whichever method you choose, the same principles apply: cool water, a gentle wool detergent and as little agitation as possible. The less stress you put on the fibres, the longer your knitwear will keep its shape and softness.
Preventing Bobbling and Moths
Looking after knitwear is about more than washing. Expert advice on knitwear care focuses on three things: careful cleaning, moth prevention and smart darning. Washing wool correctly keeps the surface of the fabric in good condition, and smart darning keeps small areas of damage from ruining a favourite jumper. Prevention is always easier than repair, and a well-cared-for wool garment can stay in your wardrobe for decades.
Frequently Asked Questions
Here are the answers to the most common questions about washing wool knitwear at home.
Can you machine wash wool knitwear?
Yes, you can machine wash wool knitwear when the care label allows it. Turn the garment inside out or place it in a laundry bag, add a wool detergent and set the machine to the wool or gentle cycle. Always use a temperature of 30°C or lower, because washing at a higher temperature risks shrinking the garment. Hand washing remains the gentlest option if you are unsure.
Does wool shrink in the wash?
Wool can shrink if it is washed at a temperature higher than 30°C. Rubbing and over agitation can also cause the wool to felt, which permanently changes its texture. To avoid shrinkage, use cold or lukewarm water, choose a wool detergent and handle the garment gently throughout the wash. Following these steps keeps knitwear in its original shape.
Is it better to hand wash or machine wash wool knitwear?
Gentle hand washing in cold water is probably the best way to care for wool jumpers, because it gives you full control and avoids the mechanical action of a machine. Machine washing on a wool or gentle cycle at 30°C or lower also works well for many garments, especially when they are turned inside out or placed in a laundry bag. Always follow the care label.
What detergent should you use for wool knitwear?
Use a wool detergent, preferably a Woolmark-approved detergent, and follow the instructions on the label. A gentle laundry detergent designed for silk and wool is also suitable. Choosing a product made for wool helps keep the fibres in good condition wash after wash and reduces the risk of damage that standard detergents can cause.