How to Wash a Wool Blanket – A Complete Guide [2024 Update]

by blankets, washing and cleaning, wool

  • How to wash / clean a wool blanket?
  • Can you wash it without shrinking it?
  • Is there a difference between washing merino wool, alpaca and other types?

All of the above are questions that kept popping up in our inbox.

It’s only when we started researching and reached out to a few wool and cleaning experts that we realized how much of confusing and conflicting information there is out there…some of them downright wrong.

So, after a few e-mail interviews we’re finally back with clear answers. And they’re updated for 2024 to reflect new detergent options, advances in washing technology and last but not least, change in the quality of wool blankets on the market.

Let’s dive in.

We have split this guide into 2 sections:

The first one is for those who not only want to know how to clean their wool, but want to understand why it’s handled the way it is. We wouldn’t reccomend skipping it because, for long-term care, it’s critical to understand the fabric.

The second outlines precise steps on how to do it – from machine and washing to drying and stain-removal.

Beyond the steps – understanding wool

Why does wool shrink in blankets and garment and not on live animals?

credit: MinuteEarth
wool structure

The important part – wool products shrink because of the fiber construction

The outer layer of the fiber is covered in scales (cuticle cells). When these scales are messed with (either mechanically, thermally or chemically), they interlock. This is what prevents the fiber from returning to its original shape and size.

In case you didn’t watch the full video, let’s reiterate why wool doesn’t shrink on sheep.

3 reasons:

  1. Because it never rains warm water
  2. Because it never rains detergent
  3. Because nobody rubs or tumbles the sheep when when it rains

Why is that important for washing

We’re not trying to be funny here. The answer to the question above is crucial in understanding how to wash wool without shrinking it.

Goold old ways

Many of us remember at least one sweater that came out of the washing machine and was half as big. As it usually goes, it was our favorite (at least in my case).

I remember my pink Burlington with gray rhomboids that was the talk of the class in high school. That is until my mom hand-washed it a few times and then got tired of it and tossed it into a machine on a “gentle” cycle.

It came out looking like a toy. Literally. It was barely a fit for my little sister.

So, what went wrong?

Two things – the machine cycle & the detergent – plain and simple. The definition of “gentle” changed a lot in the machine-washing industry. I guess the CEOs and engineers had their own “Burlingtons” and learned from it. Today, a gentle cycle in better machines is very close to hand-washing, both in terms of the motion, speed and most importantly, temperature. Today, gentle typically means cold.

Why is is this important?

Understanding why wool shrinks is critical in choosing a machine-cycle and a detergent. We said that shrinkage happens when the scales change and interlock. We also said it happens when you interfere with their fine properties.

So, for minimal shrinkage of your blankets, you would have to plan the washing so that you interfere with the fiber minimally.

Can you wash a wool blanket?

Yes, you can wash a wool blanket but there are exceptions for machine-washing. These depend on the type of fiber, the felting process and type of wool (even sheep breed).

That would be the most accurate answer.

As we said above, if you couldn’t wash it, sheep & alpacas would shrink in the rain. And if you didn’t watch the video or read the explanation and you’re still wondering – no, they don’t shrink.

The good and the bad news for blanket owners

If you are reading this searching for answers about washing a wool blanket, we have good and bad news.

The good news is that the very process that’s problematic when washing wool (interlocking of the scales, also known as felting) is used to make the dense weave of a blanket in the first place.

It means that the fibers are already treated to interlock which makes them less susceptible to further shrinkage compared to, say, sweaters and socks.

The bad news is that you still have to follow the instruction on the label. We do live in day and age where many companies make labels willy-nilly and just slap a label listing that a product cannot be machine washed to protect themselves from refund requests.

Wool is an exception here – here’s why

Different types of wool have very different shrinkage properties…and we’re not only talking about alpaca vs. merino wool. It goes beyond that. There are significant differences even between sheep breads.

On top of that, only the manufacturer knows how the wool is treated to make it dense enough.

Combine the two factors and you have reason enough to strictly follow the instructions on the label.

wool label

Rules of thumb for machine washing

We have finally gathered enough understanding to get precise about how to wash wool.

We could have just listed these straight away, but it’s better that you understand why because you now understand the principle which it’s much less likely to make a mistake.

If you are machine-washing your blanket, stick to these rules:

wool blankets washing in machine

4 rules

  • No machines with a central agitator – machine with an agitator are too aggressive (mechanically) for wool. Even the gentlest cycles will affect the fibers. If you own one, you’ll want to use a laundromat.
  • Cold water only – make sure that your chosen cycle runs on cold water. Even lukewarm might be too much, depending on the type of wool.
  • Dedicated detergents only – wool is not cheap and there is no excuse in being lazy enough and using what you happen to have on hand. It’s the most common mistake.
  • Wash one blanket at a time

By following the three rules above you’re covering all the shrinkage factors – the mechanical, thermal & chemical. The list can also be used as a guideline on how to wash merino wool, wool socks and sweaters.

Hand-washing wool

You can’t hardly go wrong with hand washing and this applies to all wool fabrics. Using just a touch of soap, or a mild detergent (preferably one made for washing wool or other delicate materials), and cold or lukewarm water, will do the trick.

Ten minutes soak and a good rinse is a good rule of thumb. To squeeze out the excess water, gently roll the blanket in a towel and press over it.

hand washing wool
no machine drying label symbol

How to dry wool

After washing, roll the garment in a towel and gently squeeze. If it’s the scarf, or some other smaller piece, you can gently twist it.

The wool garments should be dried on a flat surface, away from the direct sunlight or heat. The sun can damage the color of the fabric, especially when the wet piece is exposed to it. You can put a clean towel beneath your garment so it can absorb the water in the process.

Stay away from the dryers, if it’s not said otherwise on the label, and store as explained when completely dry.

Stains

In case of the mild stains, rinsing with seltzer can help. Just bloat the stained area with a clean cloth when you’re done.

For more serious stains, you need to put a clean cloth over it to absorb any excess liquid. Take a knife or a spoon and scrape out the stain if possible. After that, you should soak a linen cloth in a mix of white vinegar, wool detergent and cold water in equal parts, and dub the stain with it.


Dubbing inwards

When dubbing, work your way inwards, and on both sides of garment, keeping the spreading of the stain under control. Same thing can be done by applying a small amount of eucalyptus oil.

Then proceed to wash it as explained. If you are hand washing it, you can use a mix of white vinegar and water to rinse out. In the stain persists, consult your dry cleaner, they will probably know how to help you.

General care

brushing wool blanket

Airing your wool garments or blankets is the easiest way to get rid of the odors, and prolong the time between the washes.

Some of the wool garments can be put on hangers, but to avoid sagging, it’s best to lay them on the flat surface, in a ventilated space, at a room temperature.

You can do this outside, of course, just choose a warm, breezy day, and don’t expose the wool to the direct sunlight, because that will make it yellow and look aged.

If you want to refresh your wool garment, just hang it in a steamy bathroom. Moisture will fresh it up and it can even remove wrinkles.

To remove the dust and dirt that stuck to your wool coat during the day, use a soft brush and brush it down lengthwise.

Pilling

removing lint from wool roller

Pilling is something you will have to deal with, most definitely. Arm yourself with lint rollers, pill shavers and in extreme cases, scissors and razors (just be very careful using the last two).

To limit pilling to the minimum, wash your wool garments inside out, and try liquid detergents that are made specifically for washing wool or delicate laundry.

Moths

moths on wool

When it comes to moths, prevention is the key. Your wool clothes should only be stored when it’s clean. Use bags filled with dried lavender or cedar wood and place them or hang in your wardrobe.

Not only do they smell great, but they work as a great insect-repellant. You can also use chemical products that work on the same principal.

Speaking of wardrobe and storage, the golden rule for storing wool is ‘fold knits, hang woven’. You should use padded or shaped hangers, stay away from weak, plastic ones. Invest in some zipped bags for the clothes you don’t wear that often.

The takeaway

That pretty much concludes our guide on how to wash / clean wool.

The takeaway should an understanding of why wool is specific so that you can apply what you know when in doubt.

If you still have dilemmas, ask away using in the comment section below. If we don’t know, we’ll find out and get back to you (typically within a day).

Bob Ozment

Author

  • Bob Ozment

    Bob has been testing and writing about all things sleep (and especially blankets, air mattresses and folding beds), for 8+ years now. before that, he worked as a Quality Assurance Manager with one of the bigger names in the sleep industry. He holds a masters degree Statistics, Actuarial & Data Sciences from the central Michigan University at Mount Pleasant. He's one of the people who designs our producing testing and statistical models. He’s a stomach sleeper, but nobody’s perfect.