How to Wash Merino Wool Activewear: It’s Easier Than You Think

Woman holding laundry basket wondering how to wash merino wool

You’ve bit the bullet and bought that $40 pair of merino wool hiking underwear and now you don’t want to screw it up when figuring out how to wash merino wool clothes. They are not like bargain panties that you could throw away without much thought if something happened, right? Buying merino wool clothing is an investment because let’s get real those price tags are big. But caring for wool sounds scary. It sounds like there are so many rules.

Fear not… it’s really not that hard. And actually, contrary to what you’ve heard it’s pretty hard to destroy merino wool. Your merino wool underwear, base layers, t-shirts, leggings and even your socks will survive most anything you do to them with a few simple steps when doing your laundry.

First let me share that I’m a lazy laundress. I don’t have time or desire to run 7 different tiny loads to keep everything separate. I don’t want a shelf full of laundry care products. Simple is my game. I’m famous for immediately sending off to Good Will any clothing item that comes out of the dryer wrinkled. I just don’t think laundry should be an important part of our lives.

In spite of everything you might have heard, washing merino wool fits perfectly into the life of the lazy laundress. I’m going to give you a whole bunch of advice below to keep your clothes like new practically forever. However keep in mind, you really can’t mess it up and if one of these “rules” doesn’t fit your life in the moment, don’t worry about it! Merino wool is pretty hardy and will probably survive any mistake you make.

You likely already have everything you need to wash merino wool in your laundry room. I did include a few links to products we suggest if you don’t have something in the notes below. Those links are affiliate links and we may earn a small commission if you make a purchase.

The Simple Rule for How to Wash Merino Wool

The simplest and best way to wash merino wool activewear is usually to wash with your regular laundry in cool water and any liquid laundry soap that doesn’t contain bleaches or fabric softener. Then either hang dry or dry flat.

See… not hard at all.

When travelling, you can also quickly hand wash your favorite undies or socks in mild soap and then hang to dry overnight. More on how to hand wash merino wool below

Things You Should Know About Washing Merino Wool

Always read the label for laundry instructions before you buy clothes for hiking, skiing, running and all those fun active days. If it says hand wash only, think twice about make the purchase. Imagine coming in from 5 days of hiking and camping, all stinky and sweaty. Do you really think you’ll remember to pull out that one merino t-shirt that is hand wash only? Nope, it will all get dumped into the same washer load. Most merino wool does great in the washing machine, so just watch out for that one exception.


We love, love, love merino wool for hiking, skiing and just all around busy days. It keeps you comfortable no matter what the weather. Here’s several of our guides to some of the best merino wool garments for out on the trail:

Best Men’s Underwear for Hiking: No More Stinking and Chaffing
Best Hiking Underwear for Women: No More Skanky Feeling
Best Merino Wool Base Layers: Stop Freezing!
Warmest Glove Liners: Keep those Fingers Toasty Warm


Tips for How to Machine Wash Merino Wool for a Longer Life

I’m going to give you a bunch of tips for machine washing your merino wool active wear. However keep in mind that if your clothes just get thrown in with everything else and your forget all “the rules” your clothes will be just fine (except maybe hot water or hot dryers). These tips are intended to keep your merino wool clothes looking better longer. It’s worth a little extra effort to protect your investment.

  • Separate dark and light clothes, especially if they are new. New merino wool will often release small amounts of the dye in the water during their first few washes. This is how white undies get turned pink, or more realistically ugly shades of gray.
  • You should wash merino wool on a permanent press or gentle cycle. These cycles have a slower agitator rate so will not pull your clothes out of shape. It is important that all soap is rinsed out so don’t use ‘short’ cycles. Soap left in the fabric will coat the fibers and keep the wool from doing it’s natural work of breathing and wicking away the sweat from your skin.
  • Use cool water to avoid shrinking. We go into all the causes of shrinkage below.
  • You can use regular laundry detergent as long as it doesn’t have fabric softener, whiteners, bleaches or other laundry enhancers included. I use All Free and Clear for everything so it’s also perfect for our wools.  If your regular laundry detergent is the super-power stuff, it’s worth investing in a bottle of special laundry soap for wool like Wool and Cashmere Shampoo for The Laundress.
  • If you use a powder laundry soap, dissolve it first before adding your merino wool clothes. It’s easy… just let your washer fill with the soap added and then agitate a couple times before you drop in your clothes. Why? The open fibers in merino wool will tend to catch the dry particles from the laundry soap and that can cause unnecessary wear on the fabric.
  • No fabric softener. It coats the fibers which then eliminates all the little air pockets that make merino wool perfect for insulating and breathable fabric.
  • Close the zippers on all clothes in that load. The teeth of zippers can rub against the wool, snagging and occasionally tearing the fabric.
  • Don’t wash with anything that has velcro. Velcro snags worse than zippers.
  • Take our of washer as soon as done so they don’t retain the twist from the spin cycle.
  • Consider using mesh laundry bags to keep clothes from getting twisted around the wringer. This is especially helpful for smaller items like underwear that somehow manages to get one leg over the wringer and then get stretched out like a contortionist.

About Handwashing Merino Wool

The thing we all love about merino wool is that it wicks away sweat from our skin and then dries quickly. That’s what keeps us from feeling clammy on the trail. Hand washing won’t remove all the body oils (perspiration) that dry in the fabric, so although handwashing is great when you are on the move, make sure you machine wash occasionally.

  • When hand washing use just a touch of a mild detergent soap. No laundry soap with you? A simple dish soap works great. Or in a pinch you could use a shampoo that doesn’t have conditioners or fragrances in it. The less additives in the soap the better to retain the natural characteristics of the merino wool.
  • Let soak for 5-10 minutes in cool soapy water, occasionally swishing around. Then rinse well in cool water. It’s important to get all the soap residue out, which is why we only started with a little bit of soap.
  • Don’t wring out after handwashing. That will stretch your clothing out of shape. Instead press between towel layers to soak out extra water. No towel handy? Fold up your garment and press the water out against a flat surface. Then lay flat to reshape before it dries.

How to Avoid Shrinking your Merino Wool Clothes

Is your biggest fear that you will shrink your favorite merino wool shirt? I think it’s important to understand that what causes wool to shrink is the tightening of the fibers in the fabric. The wool fibers generally tighten in response to high heat or harsh chemicals.

Some people make the mistake of trying to dry their clothes faster by putting near a heat source instead of a dryer. Face it heat is heat, and the fibers will still tighten. So air drying your merino wool clothes at room temperature is generally best.

However… the more synthetic fibers blended with merino wool, the more tolerant clothes are of heat. That’s why if your favorite merino sock decides to hide and ride along with your other clothes in the dryer you don’t see much, if any, shrinkage. Most great hiking socks are a blend of synthetics and merino wool in order to increase stretch and durability.

How to Stop That Ugly Pilling

Pilling is the number one complaint you will read about in reviews for merino wool activewear. It is when those little ugly balls form on your clothes. They are most common in areas where the fabric rubs together as you move like under your arms and between your legs, however you can find pilling anywhere on your fabric. It makes your really expensive merino wool clothes look like crap.

Pilling doesn’t have to be a problem. And once you understand it you can easily avoid it.

The cause of pilling is friction against short fibers in the wool fabric. When something, like another piece of fabric, rubs against the short fibers, they roll up into little balls that stick to the material.

As you probably know, merino wool naturally has long strong fibers. That’s part of what makes it the fabric we love for our active lives. But in processing the raw wool to make fabric some of those fibers naturally get broken. It’s just the way it works. Merino wool fibers can also be broken in a finished fabric by using harsh detergents or washing machine agitators that beat the heck out of your clothes. Hence why all the instructions above about the best way to wash merino wool.

The solution to pilling is two part. And it’s not to stop rubbing your thighs together as you walk. First avoid creating more short fibers by using the basic laundry instructions above, avoiding bleaches, chemicals and excessive anything. The second is to “flush out” the short fibers that are natural in a new fabric. You can easily do that by washing your new merino wool activewear with a pair of jeans after your first couple wears. There’s something magical about denim bumping against merino wool that causes those short fibers to release from the fabric and wash away.

Other things you can do to reduce creating new short broken fibers is to turn your garments inside out when washing. And don’t overload your washer so the fabrics aren’t forced to rub against each other. If you have a stain treat with stain remover by blotting, not by rubbing the fabric against itself.

So what if you do all this and still get pilling? Gently use a Sweater De-Pilling Comb on the problem areas and problem solved. This takes a little bit of patience and time to get the results you want, so your best bet is to follow the avoidance step first.

Drying Your Merino Wool Clothes

Line dry most clothing articles. Remember merino wool dries quickly so it’s not like you’ll have clothes hanging in the bathroom for days. For heavier garments, like sweaters, it is better to dry flat to avoid stretching. Although totally optional, a dryer thing like this OXO Good Grips Drying Rack that allows air to circulate all around is pretty amazing for a quicker dry. I love this one because it is easy to fold up and store away.

The exception to line drying are articles that have high blend of merino wool with nylon/Spandex/Lycra/elastane like socks. These can often be dried in the dryer. It’s always better to check the label first. If in doubt, line dry.

Frequently Asked Questions:

Can you put merino wool in the dryer?

Although air drying is best for most merino wool clothes, if you are caught in a pinch use an air fluff type setting on your dryer. Merino wool is known for naturally drying quickly so by using air fluff you will move nature along quicker. If your merino wool item has a blend of synthetics, such as socks and some underwear, it can withstand a light heat in the dryer. Avoid using the dryer, even on air fluff, for bulky items like sweaters because they will stretch as they are tossed around in the dryer.

Should you dry clean merino wool?

Generally you won’t dry clean your merino wool. That is a chemical process that can break down the fibers. In the end you’ll have more broken fibers, which means short fibers, which means itching and pilling. The exception is structured clothes like suit jackets. As always, check your labels before you purchase so you know exactly what to expect when cleaning your merino wool clothes.

Can You Iron Merino Wool Clothes

Yes, but why would you? Merino wool is naturally wrinkle resistant. Occasionally touching up with a light iron won’t hurt your clothing. You should not plan to iron it regularly as the heat and weight of the iron can compress the wool fibers over time. That will reduce the natural insulation effectiveness of the fabric. Picture the difference between new fluffy insulation in your attic and old flat smooshed insulation. Which one is better for maintaining your home temperature? That’s exactly how merino wool works against your skin.

Can you Unshrink Merino Wool?

I’ve been lucky and never needed to unshrink a merino wool garment, because as I mentioned it’s actually hardier than you think. But if you do find yourself in a spot because your favorite pair of long underwear look like capris for your 10 year old niece, then according to Country Living Magazine you can unshrink merino wool garments with a little patience. The jist of it is that you should soak the garment in a tub of cool water and hair conditioner. The hair conditioner will help relax the compressed fibers.

Then soak out all the water with a towel. (Don’t wring – remember that causes weird shapes). Last lay the garment out flat on a towel and slowly pull into the proper shape. Then let it dry.

How Often Should You Wash Merino Wool?

It really depends upon how sweaty you get. Most people say to wash every 3-4 wears. But there is really no reason merino wool clothes can’t go a full season before you wash them. In theory, merino wool activewear will stay free of odors caused by bacteria and fungus for many, many wears because the moisture in your sweat quickly evaporates. However you body oils that don’t evaporate will adhere to the fibers and if you can imagine, the oils start clogging up the natural evaporation system. The reason you wash your clothes is to remove those oils.

What is important is to make sure you thoroughly wash your garments before you store them at the end of the season.

How Should You Store Merino Wool Clothes?

You should be very afraid of moths and silverfish. Pack away an unwashed pair of merino wool long johns and these critters will find it an have a feast. Moths love to lay their tiny miniscule eggs near a good food source. And nothing is more attractive than human oils that permeate dirty merino wool.

The most important rule of storing merino wool is that it must be cleaned before storing. Get rid of the temptation!

In addition to cleaning, you should store in containers that moths and silverfish won’t be able to or won’t want to enter. You’ve heard of the old fashioned cedar chests. Well this Cedar Lined and Breathable under bed storage bag is an absolutely perfect modern substitute.

I hope you enjoy your merino wool clothing. We just love, love it for keeping us warm in the winter and cool in the summer. Nothing beats it for life on the trails. Just don’t stress out over how to wash merino wool. As you can see, it’s really quite simple.  How to Wash Merino Wool Clothes after a busy day on the trails. Here's your guide to keeping it simple! #WalkingTheParks #MerinoWoolCare