Merino wool has a lengthy history that is more interesting than you might initially think. Long story short, it has been a favourite for military uniforms and workwear for a long time, the death penalty associated with exporting sheep and wool was lifted a long while back and Coco Chanel created a Merino wool dress that really threw the material into the limelight.
Aside from being having a fascinating history, the material itself is phenomenal. It has a ton of pros, very few cons, and a bundle of features that make it perfect for hiking.
What is merino wool?
Merino wool comes from, that’s right, merino sheep. They’re the ones with super luxurious-looking fleeces and long curly horns.
It’s different from regular wool in that it has extremely fine fibres, which mean clothes and garments made out of it don’t have any of the itchiness that normal wool does.
It’s comfortable to wear next to the skin and used to make all kinds of hiking clothes from socks to t-shirts. It’s probably one of the most popular materials for hiking clothes thanks to its incredible properties.
What’s so special about it?
1. It is perfect for summer! And winter, spring, and autumn.
Merino wool is basically magic in motion. It is worn by locals in the Sahara desert to keep cool, as well as basically everyone who is trying to keep warm. Small pockets of air within the fibres of the wool trap air inside and the crimped shape of the fibre means that it traps more air than other materials. If this warming mechanism sounds familiar, it’s because down works the same way.
As for its cooling properties, moisture is absorbed from your body (see more on this in the sections below) and stored within the wool fibres. It evaporates as your body heats up. The hotter you get, the faster the evaporation occurs. Evaporation is what occurs when your hot cup of coffee cools down when you forget about it, or how sweating can cool us down. So, this is an awesome feature to have in a fabric.
There are tons of hybrid products available that enhance the natural properties of Merino wool in an effort to intensify the effectiveness of their natural properties. For example, Patagonia mixes Merino with recycled polyester in their base layers to improve durability and Icebreaker couples it with TENCEL (a eucalyptus-based wood fibre known for its hard-core sustainability) in their summer specific “Cool-Lite” range. These additions aren’t essential for comfort, but (sometimes) they don’t hurt. Just make sure you do your research before considering items that drastically lower the content of Merino wool within the product.
2. It protects you from the sun.
Merino wool provides protection from the sun. The protection differs from product to product, but it isn’t uncommon to see ratings between UPF 30+ and 50+. This protection comes naturally, without requiring chemical treatment, so that’s an added bonus for those of you who are conscious about what you’re putting onto/into your body.
3. You’re not likely to stay wet.
The structure of the Merino wool fibres means that it is a moisture-transporting powerhouse! On top of that, it also transports moisture vapour away from your body. In simple terms, you’ll stay dry. In more complex terms, the vapours are absorbed by the wool fibres, transported, and then released to the drier environment outside of the fabric – much like the process that makes Gore-Tex so effective.
The material itself is also exceptionally breathable and its ability to absorb moisture and still feel dry to the touch borders on being absurd. In fact, it can absorb about 33% of its own weight in moisture and still feel dry to the touch. Synthetics feel wet after they have absorbed about 7% of their own weight in moisture. You’ll feel dry, comfortable and less clammy wearing Merino than you will in most (if not all) synthetics.
4. Weather – it retains warmth when wet.
This feature can be a life-saver when hiking. Literally. The “How Stuff Works” website explains that the structure of the Merino wool causes a chemical reaction of which heat is a by-product when it becomes wet (don’t worry, the air pockets discussed above keep you cool when you’re hot and sweaty). Couple this with mild water resistance as a result of the waxy coating and its abovementioned ability to absorb moisture and you’ve got yourself one very reliable fabric in the great outdoors.
5. It is fire-resistant and flame-retardant.
Merino wool is highly resilient to flames, which makes it a much better choice to wear around campfires! As an added bonus, the material won’t melt or stick to your skin and tends to simply smoulder and then extinguish, instead of igniting, when it’s exposed to open flames. Far less chance of you reaching out to your first aid kit with this on.
6. It’s anti-microbial and resists odours
Merino wool can be worn for days without smelling, courtesy to its antimicrobial properties and the lanolin that exists naturally in the material. In fact, it shouldn’t be washed very often at all. I’m a distance runner who loves to get out and hike during my holidays and long weekends. I also sweat heavily when exercising – to the point of being laughed at by my less sweaty friends. I own just two Merino shirts and have never found myself in a situation where I have nothing to wear for a run.
I just hang the shirt up to dry after a run or a day of hiking and it’s good to go. I wash them occasionally (in the region of bi-monthly to quarterly) because I feel like I need to. This “need” is purely psychological, however. If I was washing them based on the age-old sniff test, I could definitely put it off for even longer.
7. You can pack lighter.
All of the above properties combined means that your essentials packing list for a hike of any length becomes a lot shorter when you throw some Merino Wool products into the mix. I’ve survived two weeks of hiking and camping with just two Merino shirts, hiking shorts with Merino lining (no undies required, woo!), a Merino wool neck gaiter, light down jacket, a raincoat and two pairs of Merino wool hiking socks (I’ll admit, I did bring a huge comfort pair with me too for the cold nights, but even these were a Merino blend. Could I have survived without them? Yes, easily.) Plus the tent and equipment, obviously.
8. It is so soft!
No more shoving your feet into crispy socks on day three of your hike! Enough said.
9. It is ridiculously resilient.
The structure of the fibres in Merino wool has been compared to human skin. The individual fibres can purportedly be stretched in any direction 30,000+ times without being damaged. For comparison, cotton can be stretched in the same way just 3,000 times. This means that it is perfect for repetitive movements, like hiking, and won’t show the tell-tale signs of wear as quickly as other materials might.
10. It won’t make you itchy.
Merino wool fibres are fine, flexible and soft. As a result, they won’t irritate your skin – unlike other wool products. Many of the offending wool products have wide fibres that don’t bend when pressed up against your skin. This means that it will feel abrasive and prickly. However, the Merino wool fibres have a tiny diameter, so they bend when they are pushed up against the skin. Their diameter is about one-quarter of that found in human hair. That’s right, your body will be more offended by the prickliness of human hair than it will about Merino fabric.
Now I know that there are negatives associated with Merino wool on the sustainability front, but the positives that can be drawn are that Merino wool saves on water usage from washing, it is biodegradable (unless chemically treated) and isn’t made from plastic – if that’s important to you. Merino sheep actually need to be shorn every year, so it’s renewable as well.
For balance, the cons associated with Merino are:
The cost: It is usually more expensive than the synthetic options available. However, it’s difficult for me to consider this as a proper “con” because you don’t need to buy as many products, nor do you have to replace them so frequently.
Mulesing: PETA and the like often highlight that the sheep may suffer when mulesing occurs. Many companies have responded to the public pressure and it is now easier than ever to find traceable, non-mulesed wool that’s as good for your skin as it is for your soul.
Durability: Lightweight Merino wool may be less durable than other fabrics. Producers have responded to this by creating hybrid products and sometimes mix in nylon or other synthetics to improve the durability of the Merino wool at its pressure points. I personally favour mid to heavyweight Merino products and have no issues with durability, but, if this is a concern for you, grab a hybrid product and take advantage of the properties of Merino with some added durability.
Weight: There are a few products around that beat Merino on the warmth to weight spectrum. Fleece and down both tend to be warmer for its weight than wool, so if you’re going to be in a t-shirt all day and just need the extra warmth at night – other materials have Merino pegged here. If you’re likely to be wearing the jumper when you’re sweating, you should toss up how often you’re likely to be wearing it and compare the pros and cons of the lighter weight of synthetics vs the superior moisture management and insulation offered by Merino.
Anecdotally, the TENCEL/Merino blend is also preferred by many is it can reduce odour even further. This isn’t something I have personally noticed, but bear it in mind if this is of particular concern to you.
All that said, I’m sure you’ll all become instant Merino converts after buying your first shirt or neck gaiter. So, at this point, I’m happy to inform you that you can buy (almost) all of your hiking essentials in Merino. Merino underwear, Merino socks, Merino shirts, Merino jumpers, Merino base layers, Merino keychains and tea cosy’s* – you name it, it probably comes in Merino.
Here are some features you might see on Merino clothing when you go in to buy it! Here are some common terms and what they mean for you:
Microns – refers to the fineness of the wool fibres and smaller numbers equal softer material. You can normally find merino wool clothing made of fibres of between 17.5 and 24 microns. Anything less than 19.5 microns is soft enough to be worn directly against the skin and anything more should be kept for mid layers to avoid that scratchy feeling we all hate.
GSM or G/M2 – is the grams per square metre and relates to the thickness of the yarn. As a general rule, 150-200gsm Merino is great as year-round underwear. Anything over 300 gsm is good for 3 season outerwear. If you run cold, you’ll want to look for higher gsm products.
100% Pure – means that the product is not a hybrid product. The tag will also often tell you where the Merino has come from.
Final bit of advice, follow the washing instructions on the tag and get used to not washing the products very often. You won’t do your Merino wear any favours by washing it too often or with the wrong type of soap. No point destroying the fabric with harsh chemicals and frequent washes when nature designed it to not need that sort of treatment.
*(Okay, we admit that the keychain and tea cosy may not be essential for your upcoming hike – but some of the products are so cute you might not be able to resist!)