How to Wash Merino Wool Socks

washing machine full of merino wool socks

If you’re standing by the laundry wondering how to wash Merino Wool socks, you’ve come to the right place. We wash a lot of socks at Darn Tough – over 330 laundry loads a day – so it’s fair to say we have sock care down to a science. 

Before I get into detailed sock washing instructions from our sock care experts, let’s take a look at why it matters how you wash your socks, and when you should put this knowledge to use.

When to Wash Merino Wool Socks

The first question to ask yourself is if you should be washing your socks.

I never used to ask myself this question because, to me, the answer was obvious. Feet are gross and prone to stinking, so you should wash your socks after every use. That was before I got Darn Tough socks and learned about Merino Wool.

Merino Wool: Naturally Odor-Fighting

Darn Tough knits most of their socks from Merino Wool. Merino Wool socks (and other Merino clothing) are different from your run-of-the-mill cotton or synthetic socks, because Merino Wool is naturally odor resistant.

The wool fibers’ unique properties prevent the buildup of sweat while also locking away odors. In other words, Merino Wool clothes stay fresher longer, even if you put them through the workout wringer. You don’t need to wash them every time you wear them, meaning you can go longer between wash cycles and save money at the laundromat, all while reducing your environmental impact.

Pile of darn tough socks ready to go in the laundry

Not going to lie – I read all the research about Merino Wool’s anti-stink properties and was still skeptical. Stinky feet run in the family, and I don’t like to encourage it.

To test my new knowledge, I re-wore the same socks for multiple workouts, held them up to my nose, and took a hesitant whiff. No stink. Not just less stink, but actually none at all. Don’t believe me? Give it a go.

How Often to Wash Your Socks

So how often should you wash your wool socks? That depends on how long you wear them per use, the activity, climate, and your own comfort level with re-wearing clothing.

I’ve found washing them after 2-3 full days of wear to be a good balance. That said, I have some friends who’ve worn them upwards of a month.

Why You Should Wash Wool Socks Differently

When it does come time to wash your Merino Wool socks, you can choose to just throw them in the washing machine with the rest of the laundry on whatever setting you normally use…but we don’t recommend it. Here’s why.

Merino Wool socks aren’t like other socks – Merino Wool fibers are naturally special. The fibers are why the socks can fight odor, why they’re warm on cold days and cool on hot days (a property called thermoregulation), why they’re soft and cozy against your skin, and contribute to a good, snug fit that keeps blisters at bay. Properly washing your wool socks helps protect the Merino fibers, keeping them in tip-top shape.

Darn tough mill worker drying our merino wool socks

The good news is Darn Tough socks are Guaranteed for Life, regardless of proper washing technique. So if they do wear out, you can get a new pair under our warranty.

But in the interest of reducing waste and making your favorite socks last longer, follow the below care instructions on how to wash Darn Tough socks. Your socks will thank you, which means your feet will, too.

Probably worth checking the wash and dry instructions on any other Merino Wool garments you own, too.

How to Wash Merino Wool Socks

An infographic showing the steps of how to wash merino wool socks using a washing machine

Here are the machine washing instructions for Darn Tough Merino Wool socks (that's right, you don't have to hand wash them). You can also follow the same steps if you have a pair of Darn Tough synthetic socks or compression socks.

In case you’re washing them far from home, I included special instructions for washing socks by hand in the backcountry below. There’s also a quick list of sock care don’ts you should hang on the wall in your laundry room.

Darn Tough Sock Washing Instructions

  1. Turn your socks inside out.
  2. Wash in cold water on the gentle cycle.
  3. Choose a mild detergent with a neutral pH.
  4. Tumble dry on low or air dry.

#1 Turn Your Socks Inside Out

Before washing your socks, turn them inside out. This is especially important for socks that have cushioning, which is created by terry loops. A lot of debris and dirt can get caught in those loops.

Turn merino wool socks inside out before placing in the washing machine

#2 Wash in Cold Water

High heat can weaken fabric fibers and fade colors, so you never want to use hot water. Use a cold water* wash on gentle cycle. If your machine has a knit or wool cycle, you can use that setting.

Consider using a laundry bag to minimize the chance of missing socks. The bag also helps protect your socks from catching on or rubbing against other, potentially abrasive, items in the laundry.

In the backcountry: Fill a watertight bag with cold water and allow the socks to soak in it for about 10 minutes.

*We updated your wash instructions in 2023 to cold water washes. Previous instructions said warm water or cold water, and you may still see those instructions as the update rolls out. We now recommend only cold water for two reasons:

  1. After much testing, our team found cold water washing helps the socks maintain proper fit better than warm water over time. 
  2. Cold water washing is an easy yet impactful way to benefit the environment, as it uses less energy. And the warm setting on your washer isn't hot enough to wipe out bacteria (but the sun's UV rays can)

#3 Use the Right Laundry Detergent or Soap

When cleaning your socks, choose a detergent with a neutral pH, no acids or alkalis, as these can weaken sock fibers. Woolite® and Nikwax® Wool Wash are two good options. Make sure not to use bleach, and do not add a fabric softener.

In the backcountry: Use a biodegradable soap like Dr. Bronner’s®. Make sure to follow Leave No Trace practices and any regulations specific to the area you are in.

  1. Add a small amount of soap and gently agitate and shake the bag.
  2. Wait 15 minutes, then shake the bag again.
  3. Drain the water at least 200 yards from any water source.
  4. Refill the bag with fresh water and shake again to rinse out the soap.
  5. Drain the water. Repeat Steps 4 and 5 as necessary until soap is removed from the socks.

#4 Air Dry or Tumble Dry Low

Line drying wool socks is great for the environment, plus you can capture some fun pictures of your socks all lined up to dry. If you’d like to speed the process up, you can put your socks in the dryer. Make sure to set to tumble dry on low to avoid excess heat wearing down your socks.

Laundry line of darn tough merino wool hiking socks hanging to dry

In the backcountry: Use your palms to gently press out excess moisture. Lay them on a rock or tent line to dry. If you hand wash your socks in the morning, you can attach them to outside of your pack to dry as you hike.

Bonus Step: Fold Your Socks (Don't Roll)

If you really want to go the extra mile with your sock care, choose to fold your socks. When you store socks by rolling the top of one over the other, it unnecessarily stretches the socks and can cause them to be misshapen or lose their stretch faster. Storing them flat or folded lets the fibers naturally relax.

We tested and rated 5 sock folds to get you started.

Darn tough mill worker folding our merino wool socks

Darn Tough Sock Care Don'ts

High heat and harsh chemicals can damage the magic Merino Wool fibers that give your socks top-notch performance abilities. To protect those fibers, remember these five sock care rules:

  • Do not dry clean.
  • Do not use bleach.
  • Do not use fabric softener.
  • Do not iron.
  • Do not wash as often.

What About How Wool Shrinks?

I hear this question a lot, wondering if the wool won’t just shrink in the laundry. If you have Darn Tough socks, you don’t need to worry. Our socks are all preshrunk. We washed them before they ever left Northfield, Vermont.

The laundry room in Northfield, Vermont

When you do wash your socks, you may notice that, like a pair of jeans, they feel a bit tighter after being freshly washed, but they’ll relax again as you wear them.

A Little Sock Love Goes a Long Way

A saying that’s true for socks, among other things. Following the above sock care tips can help you get the most out of your Merino Wool socks while keeping them clean and fresh. I also recommend periodically cutting your toenails, but that’s a conversation for another day.

TL;DR — Sock Washing FAQs

How often should you wash wool socks? Merino Wool socks don’t need to be washed as often. You can easily wear them 2-3 times before washing, and some people go longer.

How do you wash wool socks? Turn your socks inside out and wash in cold water on the gentle cycle. Use a mild detergent; avoid fabric softeners and bleach.

Do you wash socks in hot or cold water? Wash your wool socks in cold water. Never use hot water, as it can weaken the fabric fibers and fade colors.

Should socks be washed inside out? Yes, turn your socks inside out before washing them to clean out the sweat and dead skin cells from your feet.

Can you dry wool socks? Yes, you can tumble dry our Merino Wool socks on low. Line drying your socks is great for the environment.

Can you wash socks with clothes? Follow the washing instructions for your socks. If the clothes you’re washing can use the same settings, you can wash them together.

Do Darn Tough socks shrink? No worries, all our socks are pre-washed and pre-shrunk, so they won't shrink on you. If they feel a bit tighter after coming out of the show, it's not unlike how a pair of jeans feels smaller after you wash them. Our socks go through the same fabric recovery process and will relax with a little wear.

About the Author

Jenny Hastings fell in love with hiking from spending hours in the White Mountains with her dad, spending most weekends in the summer and quite a few weekends in the winter out on the trails. She's always looking for a new summit and ways to spend more time outdoors, whether on the trail or reading in her hammock.