Why Merino Wool is the Holy Grail for Thru-Hikers: The Soft, Odor-Fighting Fabric You Need

Merino wool's natural odor resistance and moisture wicking make it the ultimate fabric for thru-hikers. Learn why it outperforms synthetics for long trails.

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Josh Koop

I live with my wife and daughter in Katy, Texas and my local trail is the Lone Star Hiking Trail which is an amazing way to experience the Sam Houston National Park!

Man wearing a Merino sun hoody to get protection from the sun
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Merino wool has long been a favorite of thru-hikers for its superior performance and versatility. This natural fiber is soft, breathable, and moisture-wicking, making it an ideal choice for extended treks in hot weather conditions.

Unlike synthetic fabrics, wool from merino sheep does not trap heat or sweat, making it a more comfortable choice for those who tend to perspire heavily.

Additionally, merino wool is naturally odor-resistant, meaning hikers can go longer between washings without having to worry about their gear smelling bad.

What Is Merino Wool?

Merino wool comes from a special breed of sheep primarily raised in New Zealand and Australia.

The merino fibers are incredibly fine, creating soft wool, along with being non-irritating, all this makes it ideal for next-to-skin garments.

Merino wool is also much more efficient at regulating body temperature than synthetic fabrics, making it a great choice for both cold and hot weather conditions and a perfect match for thru-hikers.

The Benefits of Merino Wool for Thru-Hiking

Thru-hiking is unique as you tend to have the same clothing day after day for months after months, this combination is more than enough to demolish many articles of clothing, especially cheaper synthetics.

Thru-hikers are brutal on their clothing, needing to have it perform in various roles to deserve a spot in the backpack, for many the use of merino will be heavily used for socks, underwear, and as a base layer for maintaining warmth.

For many thru-hikers and backpackers in general the bigger costs to add this gear pay for themselves within a few trips, or for a thru-hiker a single long-distance trek.

How Merino is Made

Similar to all regular wool products, the first step is to shear the sheep, then the wool is cleaned and carded to get all the tangles out.

This process opens the fibers and readies them for spinning into yarn.

These merino wool fibers are then spun into yarn which can be used as-is or combined with other yarns to create different weights and thicknesses.

The yarn is then sent off to be made into a fabric that eventually will become clothing.

What Benefits Does Merino Wool Provide a Thru-Hiker?

So what gives, why would you look to shell out sometimes two or three times more money on a piece of gear versus the more budget synthetic options?

For myself, I sweat a lot, this leads to body odor which in synthetics can become rather gag-worthy over 4-5 days let alone months with quick short wash cycles.

Even after you wash gear, within hours of wearing and sweating again the previous stink tends to come right back.

This is why Merino is an amazing option for me as its fibers naturally fight odor and issues related to bacteria that can accumulate over days of hard blood, sweat, and tears.

Odor Resistant & Antibacterial: Kills Pervasive Hiker Stank

Probably the key to long-distance hiking is helping to make you more bearable to others around you, and most of the time to yourself.

As you go day after day the typical hiker stink starts to take over all your gear, this is where Merino really shines.

The fibers have what’s known as “lanolin” which essentially is like a built-in soap that helps fight body odor and bacteria, even better it doesn’t hold onto the stink as synthetics do.

As your body sweat (which it will do a lot of) the lanolin helps to wick away that moisture and spread it out over a larger surface area to help evaporate it faster, all while continuing to fight bacteria build-up.

Quick Drying: Breathability and Moisture Wicking

Merino works very similarly to other synthetic fabrics by being moisture-wicking, along with its ability to dry much faster making for a nice dual-threat in gear that can work in cold or warm weather.

This is due to the much finer fibers that make up merino which also help with its breathability, another area where synthetics often struggle.

This increased breathability helps prevent that swampy feeling you can get when wearing non-breathable fabrics.

Temperature Regulation: Cooling and Warming

In hot weather, the increased breathability helps to keep you cooler as your body sweat can more readily evaporate.

Then in colder weather, it helps to regulate temperature by holding in body heat but also wicking and not allowing your sweat to turn into ice crystals on your body which can actually make you colder.

This can lead to what’s known as the “chill factor” where your sweat turns to ice and you can get what feels like a cold chill even when it’s not that cold out.

In extreme cold, merino also has an added benefit over synthetics of not losing insulating properties when wet as most do, this can be the difference between life, and uh…not life.

Washable: Clean Fast and Simple With Air Dry

Merino is very simple overall to wash out on the trail and in town, as you don’t need a washing machine since it has those natural oils that help fight odor and also help keep things from penetrating deep making them easier to remove with less effort.

A simple quick hand-washing in a sink or on the trail away from water sources with some biodegradable soap can go a long way, and then you just simply hang it up to dry.

Drying time is much quicker than with synthetics due to the finer fibers, often taking much less time to be ready to wear and move on.


Merino fiber is also very strong and can withstand a great deal of abuse, this is due in part to the fact that the animals often have hardy lives where they can’t just regrow fast and some sheep live in some of the hearty conditions.

This means you won’t have to baby your merino gear as much as you might synthetic fabrics which are often more fragile. All this while still maintaining the ability to be incredibly soft to the touch!


Unlike many other fabrics out there, merino is non-allergenic which means those with sensitivities to fabrics can often wear it without any issues.

This is due to the fact that the fibers don’t hold onto dyes, chemicals, or other irritants as easily as some other fabrics do.

So if you have ever had an allergic reaction to a shirt, it was likely not the wool itself that caused the issue.

Natural Fire Retardant

Merino is also a natural fire retardant fabric that can give you some extra peace of mind in case of an emergency, this is due to the fibers being able to resist catching fire and burning as easily as some other fabrics.

While not a huge issue if you spend nights by fires or plan to be a social butterfly this can help make sure no melting occurs should you get too close to the flames.

Built-In UV Resistance

As sheep tend to be out in the sun a good deal, their wool has evolved to offer some UV protection from harmful rays.

While not as high as what you would get from synthetic fabrics that have UV inhibitors added in, it can help give you a little extra protection if you are caught out in the sun for long periods without shade.

This is often a nice surprise for those who don’t realize it since most people think of wool as being hot, but in reality, it can help keep you cooler in the sun than some other fabrics.

Organic & Renewable

As this regrows without manufacturing, it is an organic and renewable resource that doesn’t put the same strain on the environment as some other fabrics do.

This is not only good for the environment but also for those with sensitivities as there are no harsh chemicals used in its production.

You can feel good knowing that what you are wearing was grown and not produced in a lab somewhere unless you are a vegan this should be held as a perfect match to help sheep and humans live together.

Potential Drawbacks of Merino Wool

There are some drawbacks to choosing a merino base layer which include the cost and the fact that for a very small amount, it can still feel itchy and uncomfortable.


Merino is much more expensive than many synthetic options on the market, and this can be a significant drawback for some people.

The high price tag is often worth it for thru-hikers who need gear that will perform well and last long, but if you are on a tight budget, it might not be the best option for you.

Itchy and uncomfortable for Some

For some people, merino can feel itchy and uncomfortable, especially if you are not used to wearing wool. This is often due to the fibers being too coarse, and it can take some time to get used to it.

If you are someone who is sensitive to fabrics, it might be best to try a small patch first before committing to an entire garment, many times cheaper merino will use more coarse fabric to cut these costs down.


For a vegan using animal products is not an option, so they will have to choose from the synthetic fabrics which are available.

While there are some good options out there, they often don’t perform as well as merino wool and can be less comfortable in a variety of situations.

How to Choose the Right Weight Merino Wool

The grade or weight of the wool will tell you a lot about what the garment is best suited for, and you can often find this information on the tag.

The lower the number, such as 100 or 200, the lighter weight it will be and often more comfortable in warm weather. Heavier weights are better suited for colder conditions but can also be more durable.

A higher micron count means the fibers are thicker and can often be itchy, so if you are someone who is sensitive to fabrics, you will want to think about avoiding these.

Grade 100

This is super lightweight Merino and is often used in underwear or very lightweight base layers as it wicks away moisture well and is comfortable next to the skin but more fragile.

Grade 150

This is lightweight-weight merino and is often used in shirts, lightweight hoodies, or sweaters. It offers more warmth than the lightest option above and is still breathable and good for summer.

Grade 200

A bit heavier mid-weight multipurpose merino, this wool is often used for all weather conditions, frequently used for skiing garments, and Icebreaker 200 Oasis series tops and bottoms.

Grade 250

Moving into the super-warm category, grade 250 is often used for heavy warmth and requires cold-weather gear.

It’s not as breathable as the lighter options but will keep you warm in freezing temperatures while not adding lots of bulk.

How to Hand Wash Merino Gear

Washing your Merino gear is only a simple few steps, and you can do it by hand or in the washing machine.

  1. Start with a Clean Sink – This should be obvious but you don’t want anything else in the sink that could cause fabric issues.
  2. Fill With Warm Water – This will be to soak your garment(s) so make sure there is room for the water and garments without overflowing.
  3. Mild Detergent – If you have any detergent in town this is where you can add a drop or two to the water to help clean.
  4. Soak Clothing – This is when you want to add your clothing into the soapy water and let it soak for up to about 20 minutes depending on how soiled it is.
  5. Agitation – Merino shouldn’t be harshly twisted and crushed, instead you want to just gently agitate it periodically.
  6. Rinse Clothing – Drain the dirty and soapy water from the sink or tub and then rinse out your clothing with fresh water until you see no more bubbles/soap.
  7. Air Dry – Please do yourself a favor and don’t wring out your Merino gear you just need to air dry, in the sun for maximum UV and bacteria-killing.

Hopefully, this helps you to clean in town since most of the time you won’t have machines available.

Answering Common Questions About Merino Wool

How to shrink merino wool?

You can shrink merino wool by agitating it in a warm environment. You can do this by hand or in a tumble dryer.

How to unshrink merino wool?

To unshrink wool, add a fabric conditioner and stretch it by hand. However, please make sure to check with the manufacturer first if they have any specific instructions or methods that work best based on how they create the garment.

Why is merino wool so expensive?

Merino wool is expensive because it takes a lot of time and effort to make, and there is high demand for it. The combination of these factors means that the cost of merino wool is high.

Final Thoughts on Merino Wool Gear for Thru-Hiking

And there you have it, everything you need to know about why merino wool is the superior fabric for thru-hiking and what to look for when purchasing your own gear!

What are your thoughts on merino wool? Let us know in the comments below! And be sure to check out our other blog posts on thru-hiking gear and tips !

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