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How to wash merino wool

How to Wash Merino Wool

Here is a quick summary of Do’s and Don’t. Below is a list of some general tips to hand wash or machine wash your merino wool.

So, you’ve bought some expensive merino wool clothing.

You’re wondering how you can wash it without damaging your pricey purchase.

How do you avoid shrinking your merino wool in the wash? Is there a way to avoid unnecessary wear and tear?

Read the label

There are 2 main ways to wash merino wool. And no matter if you are planning to use a wash machine or hand washing it, you want to make sure you have read the label first.
The majority of the specialized merino wool brands offer garnament that are in most cases machine washable. However, better be safe and read the specification as sometimes, it can be wash in machine, or hand washed only or even dry clean only. On Merino Wool Rocks, we try to let you know if a piece of clothes we review is not machine washable as it can be a serious drawback in the long term.

In case, you can’t read the label, here’s a list of the care instructions of some of the bigger brands: Icebreaker, SmartWool and Darn Tough for merino wool socks.

Wash at Low Temperature (86°F or 30°C) on Normal Cycle

Most clothing can be washed at low or medium temperatures on normal cycles. Keep like colors together, so that means washing dark and light colors separately. I usually wash my t-shirts inside out to protect the prints.

Avoid Pilling

pilling in wool
Pilling on wool. By RyjOwn work, CC BY-SA 3.0, Link

Pilling is an annoying problem with wool where small balls of fiber form on the surface of the wool garment. Personally, I haven’t had any problems with pilling from Icebreaker, but I have had problems with other brands such as Finisterre.

Brands recommend you wash your new garments within 3 wears once you buy it to remove short fibers that cause pilling. Then, every couple of months you can wash your merino garment with a coarse fabric such as denim to flush out these short fibers that accumulate over time.

What About Wool Detergent and Wool Washing Cycles?

Wool detergents are fine for merino wool, provided they don’t include fabric softener. Fabric softeners won’t work on merino wool, which is already super soft anyway, and they risk damaging the fabric.

Secondly, wool “delicate” cycles often don’t rinse as thoroughly as normal cycles, so you run the risk of leaving detergent in the wool. That can also damage the fabric.

Therefore, most of the major brands recommend a normal cycle at 86°F or 30°C. Personally, I set the spin at the end a little lower, so it’s not as harsh.


When I’m traveling as an ultra-light traveler, I’ll only have two t-shirts with me, so I’ll operate on a “wash one, wear one” cycle. I’ll often hand wash the t-shirt in a bathroom sink.

Before you start washing, you should research on the best wool-specific soaps. Being a delicate fabric, merino wool requires a gentle washing liquid, which won’t damage its fibres. Whether you decide to use a shampoo, detergent or soap, just ensure that they are designed specifically for merino wool fabrics.

When it comes to washing, start by filling a basin with lukewarm water. By lukewarm, we mean the water should be between 85 and 100°F.

With your wool clothes fully submerged in water, soak them for about five minutes. Do not soak for longer than this because it can warp the fibres. The next step is to gently swish the wool items with your hands. The gentle swishing is similar to the rotating motion of a washing machine, and it helps the soap to penetrate your clothes and remove dirt.

Once they’re clean, all that’s left to do is to rinse in warm water. You can rinse multiple times so that you get rid of all the detergent. Also, it’s vital to use the same temperature for your rinse water as the one you used when soaking.

After rinsing, gently squeeze out excess water. Never try to wring your Merino wool fabrics because they can lose their original shape. Instead, press the water out of them.

Drying and Pressing

The short version: line dry, don’t tumble dry.

Merino doesn’t respond well to tumble drying. You’ll risk having shrunken clothes. Socks will be an exception, as they are usually a blend of merino wool with nylon/Spandex/Lycra/elastane. They can be tumble dried on low heat.

Basically, unless stated otherwise, merino wool apparel should be dried using a flat drying rack. Most drying racks are fitted with mesh surfaces, where you can place your wet clothes flat and leave them to dry.

It’s not advisable to hang any of these clothes on a hanger or line. This is because the weight of the wet fibres causes them to sag. Also, never put Merino wool near heat sources like a radiator. Instead, dry them in open air but away from direct sunlight.

One benefit of merino wool is that it’s not susceptible to wrinkling. However, if there’s a need to iron this fabric, first dry it completely. Next, turn the cloth inside out before you start pressing.

When ironing, we recommend placing a pressing cloth between your merino wool fabric and the iron. The pressing cloth simply acts as a protective shield. If you don’t have one, you can use a white cotton towel, a piece of muslin or any other fabric, which cannot transfer colour to your clothes.

With the pressing cloth in place, set your iron to wool setting and start ironing. Use steady pressure and avoid pressing one section for too long.

How Often Should You Wash Merino Wool?

Apart from its resistance to wrinkling, another perk of merino wool fabric is that it’s low maintenance. It has natural anti-bacterial and stain-resistant properties. This makes it more resistant to dirt than cotton and synthetic fabrics.

That said, you still need to keep your merino wool apparel clean. But this doesn’t mean that you toss it in your washing machine after every wear. In fact, experts recommend that you reduce the number of times you wash merino wool.

When you engage in low-impact activities, then all you need to do is to air the woolen fabric you were wearing. In case the garment has a couple of stains, spot clean them using a mild detergent.

The only time you should wash merino wool apparel is after wearing it several times or if you were engaging in vigorous activities that made you sweat heavily.

Shrinkage in Wool and What To Do About It

Woolens are great at giving us warmth. The one thing they are not so good at is maintaining their shape when they’re put in washing machines. If you don’t follow the instructions above, you might end up with a shrunken sweater.

This shrinkage that occurs when you wash merino wool is not shrinking per se. It’s only that the fibres have come closer together, causing your garment to look smaller.

So, what causes this clinging of fibres? One, using the wrong detergent. When you use conventional laundry detergents, they break down the molecules in merino wool, causing the ‘shrinking’ effect. Therefore, you should always use wool-specific detergents such as grangers wool wash or Nikwax wool wash. You should also use lukewarm water, and the delicate/woolen cycle (if using a washing machine).

If it’s too late, that is, if you’ve already washed your woolen cardigan and it seems shrunken, then not to worry. There’s a way to unshrink it. Follow these steps:

Fill a basin with lukewarm water. Add two tablespoons of baby shampoo or a hair conditioner. These products help to soften wool fibres; hence, prepare them for stretching.

  • Soak your woolen for at least 20 minutes.
  • Drain the water and gently press out excess water. Do not rinse or wring your woolen item.
  • Place the garment flat on a thick, absorbent towel, and roll it up to remove excess moisture.
  • Place the clothing on a flat surface, preferably on another clean towel, and stretch it as much as you can.
  • Air-dry the woolen and avoid making a similar mistake the next time you wash it.

How to Store Merino Wool Clothes

Most people will learn how to wash merino woolens and then neglect the storage bit. But learning how to store these apparel is just as important as washing them properly.

Now the best way to store merino wool fabrics, is to fold them, then put them in airtight, plastic containers so as to keep moths out. Vacuum storage and ziplock bags are also a good way of storing woolens. Whichever option you use, ensure the storage unit is dry before putting in the clothes. Also important to note is that woolen fabrics should be cleaned before being stored.

Anything you’d add or questions? Leave a comment below!

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