Cotton Kills! Or: Why You Should Be Wearing Merino Wool Hiking
What’s all the fuss about merino wool?
If you are somewhat interested in the outdoors adventure world you have probably heard about merino wool hiking apparel.
And I’m pretty sure you wondered if you should buy some or maybe if it’s just some kind of overblown sales pitch to make you spend more.
Because let’s be honest – high-quality merino wool clothing is not cheap. So why not stay by your good, old cotton tee?
Why you should never wear cotton when hiking
Unless you are going for a pleasant stroll in your city’s suburban park, you should wear only technical hiking apparel.
Cotton is cheap and really comfortable to wear, I agree.
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But it also takes too long to dry. It might not be a problem during a short trek on Sunday, but it can become dangerous when on a longer hike. Sweaty cotton shirt right to your skin behaves like a wet, cold compress.
It provides no insulation because all the air pockets fill up with your sweat. Cotton fabric does not have the ability to wick away moisture like the technical synthetic or merino wool do.
The moment you stop walking or climbing, your body cools down very fast, with all that water plastered on you – you are in danger of hypothermia.
And I hope you never have such a silly idea as hiking jeans, right? They weight as much as my week's food allowance and once wet (it rains sometimes) they never dry (I exaggerate only slightly).
Cotton and her evil sisters
Cotton is not the only fabric you should avoid when hiking.
All cotton blends (like cotton-polyester) or fabrics named corduroy, denim or flannel are cotton-based. In addition to that, all cellulose-made fabrics also absorb water very fast and don’t insulate when wet.
Stay away from clothing made of viscose, Tencel, Modal, rayon or lyocell. Even bamboo is not advisable – its benefits are more of a sales pitch than reality.
On the list of fabrics to avoid is also silk – highly absorbent fabric losing its insulating abilities when wet.
Wool or synthetic
Now that’s a good question. I remember how my Mom hated polyester shirts because of how they didn’t breathe and made you stink.
I internalized this message very well and stayed away from anything synthetic throughout my life. But then I started hiking again and realized that modern technical synthetic apparel is not exactly the polyester shirt from the ‘80s.
I see the choice between synthetic and wool as a personal one. I have shirts made of both fabrics and I like them. It is said that synthetic stink up faster, but many producers add special woo to slow bacteria from growing.
Synthetic materials are better at wicking moisture away from the body and usually dry faster. On the other hand, wool fabric is highly insulating even when wet – it absorbs up to 35% in its dry weight in moisture vapor but still feels dry.
That’s why you don’t feel sweaty and clammy when wearing merino base layer. In contrast – synthetic fabrics feel wet after they absorb about 7% of moisture.
My personal choice? Merino wool is always great, especially in warm and cold weather. The synthetic base layer is my preferred choice for a really hot weather when I don't care to feel a bit sweaty and the cooling effect of the wind on wet might be even pleasant.
But really - both kinds of fabrics are fantastic.
So what’s the magic with merino wool? Why is it special?
Merino sheep is a very old breed of sheep living in the mountains of New Zealand, Australia, South Africa, Italy, and Turkey.
They evolved in a climate that required thick insulating coat to survive harsh freezing temperatures but also light enough so they wouldn’t overheat in the mid-day heat.
Here's a short list of amazing qualities of merino wool:
- Merino wool has an amazing ability to transport moisture vapor away from your heat zone right next to your skin. Thanks to this you stay dry and comfortable.
- This you already knew: merino wool hiking clothes are great at keeping you warm. Wool fibers are able to trap air better than any other fabrics. All that trapped air is the perfect insulator. What’s crucial, wool keeps the warming and insulating abilities even when wet.
- What you might not have known already: merino wool hiking clothes are also awesome at cooling. What? Didn't I just write that it’s best for keeping you warm?! But just think of the sheep – they can survive very hot summer days with all that wool. How can that happen?
All that moisture that wool is able to store is cooling the air right next to your skin when it evaporates. When your body heats up and you sweat – all that moisture evaporates through the wool fibers and your body is cooling. A thin merino base layer is perfect for a hot summer hike.
- Sometimes we perspire too fast for the moisture to evaporate fast enough and the fabric needs to wick it outside. Both synthetic and merino clothing do that, but merino wool is able to wick away moisture when it is still in its vapor state.
- Thanks to the wool’s ability to move away moisture it does not create a bacteria-friendly environment. Merino apparel is famous for being stink-free even after being worn for a long time in really sweaty conditions.
More than once I have worn my merino base layer or socks for two or three days without stinking or feeling disgusting. Now that’s something in the wild!
- Merino wool is static-resistant which means it doesn’t cling to you in an annoying way or causes sparking.
- It is also fire-resistant and flame-retardant making it a good choice around campfires. It does not melt or stick to your skin – so much safer than other fabrics.
- I still remember with some horror how my father used to wear lambs wool sweater directly on his skin. As a kid, I hated woolen sweaters, scarfs or hats because of the itchy and scratchy fun.
But merino? Not your typical wool.
Merino fabrics are actually pretty soft. It is also unusually, for a wool fiber, stretchy. Thanks to it merino garments are comfortable and return to their shape after being stretched.
- It is generally claimed that merino wool is hypoallergenic. My skin is sensitive and I have multiple allergies. When I was wearing merino base layer for the first time I noticed itching and even swelling in areas under pressure: where the backpack’s belt was pressing hard the garment against my skin.
For the next few days, I was wearing synthetics and staffing the synthetic top fabric under my merino undies where the belt went…
After a few days, I put merino again and nothing like that happened again. So I am aware that there might be some irritation with the seriously sensitive where there is hard rubbing against the skin.
- Merino wool garments have better UV-protecting properties than other fabrics.
- Merino wool is of course completely natural: made by sheep, renewable and biodegradable. Every year merino sheep produce a new fleece for us to enjoy.
- The above-mentioned softness and elasticity mean merino garments are less prone to wrinkles. What is even better? You can wash it in a machine!
I’m pretty sure I convinced you to get interested in merino products. So where should you begin?
What kind of merino products should you get?
Now that you want to throw all your retirement savings on all things merino, it is worth deciding where merino is the most beneficial.
Merino base layers.
That's where merino wool products really shine. I absolutely love my short- and long-sleeved base layers made of thin merino wool.
For colder temperatures, you can get a thicker base layer and also leggings. I highly recommend them as your camping pajamas.
Check out some examples by reputable and recommended producers:
For the US visitors:
- Icebreaker Women's Everyday Long Sleeve Top,
- Smartwool Women's Micro 150 Tee or
- Smartwool Women's Merino 150 Baselayer Pattern Bottom.
For the UK visitors:
This one is the most surprising – who would have thought wearing woolen undies could be so comfortable?
I have a few pairs of merino undies and can’t recommend them highly enough. No matter how much I’m sweating, I don’t feel I hike in wet underwear.
Their odor-repelling abilities are particularly welcomed here, as well. I admit to wearing the same pair of undies for two or three days when there was no other choice and I didn’t feel stinky or dirty.
In addition to the undies, I also own a merino bra - very comfortable, although not as elastic (holding) as a synthetic one.
Still - I like hiking with it.
Check out those awesome examples of female merino underwear: US:
- Smartwool Women's PhD Seamless Bikini,
- Icebreaker Women's Sprite Racerback Bra, or
- Smartwool Women's PhD Seamless Boy Short.
- Icebreaker Women's Siren Underwear,
- Icebreaker Women's Sprite Racerback Body Fit Bra or
- Icebreaker Women's Sprite Hot Pants.
Contrary to the other kinds of garments, you probably won’t find a 100% merino socks.
They generally are made of wool blends with high merino makeup. Thanks to mixing it with other fibers, they become more durable.
There is a huge variety of merino socks to choose from for every kind of activity or season.
I don't wear merino socks directly on my feet, but rather over a think Coolmax liner. This system works perfectly for hiking in boots with a heavy backpack.
- US: Smartwool Women's Hiking Medium Crew,
- CloudLine Merino Wool Crew Hiking/Trekking Socks, or
- Bridgedale Women's MerinoFusion Trekker Socks.
- UK: Smartwool Women's Hike Medium Crew Socks,
- Bridgedale Merinofusion Trail Women's Sock or
- CloudLine Merino Wool Hiking Socks Ultra Light.
Mid- and outer-layer.
Merino wool is the perfect fiber for layering. Its superior insulating properties make it a great choice for sweaters, soft-shells, and jackets.
BUT. Heavyweight wool dries very long - so if you sweat a lot or can get wet, better stick to a good fleece or primaloft jacket.
To be honest, most of those are also way beyond my budget but must be pretty awesome to have.
Merino buffs and hats.
I have two merino buffs and I absolutely love them. I wear it not just during my hikes – often as a hat, but also whole winter in the city. For me, it’s a must.