Most hiking socks aren’t made from 100% merino wool – instead, they’re mixed with synthetic materials to improve their properties. And the percentage of merino wool in the fabric varies between models and manufacturers.
I’ve hiked with multiple merino wool hiking socks, including Silverlight, Smartwool, and Darn Tough, each with a different percentage of merino wool. So in this article, I’ll explain what sock materials worked the best for me, and explain the science behind various sock materials.
In general, your hiking socks should contain 40-75% merino wool, 20-50% nylon, polyester, or acryl, and 1-5% elastane, spandex, or lycra. Personally, I couldn’t see any significant differences between a 40% merino wool sock, and a 70% one, even after hiking long distances with them, so as long as you’re within the 40-75% range, you should be good.
A Higher Percentage Of Merino Wool Results In A Less Durable Sock
Merino Wool is made from a specific sheep breed called Merino, which has much thinner and softer fibers within its fur. This gives the material better properties than regular wool, such as improved thermoregulation, moisture resistance, and odor resistance. However, it also makes the sock less durable, especially when compared to synthetics.
Synthetic materials (polyester, nylon, or acrylic) are much more durable than regular wool, they dry quicker, and they also wick away moisture better, which is why merino wool is usually mixed with synthetics. 100% pure merino wool is only used in baselayers, hats, and glove liners, where durability and moisture resistance doesn’t play a big factor.
So having a higher synthetic content within the sock fabric will make it more durable and better for hiking in wet conditions. However, adding too much will lose the benefits that merino wool offers, and might result in a less-comfortable sock that results in more blisters.
The only minor difference that I’ve noticed personally with a higher merino wool content is that the socks develop holes quicker, and the fabric starts to look worn after a few washes.
How Much Merino Wool Should Be In Summer Hiking Socks
For spring, summer, and autumn hiking, your socks should generally contain a bit lower percentage of merino wool – between 30-60%. That’s because your socks need to be able to dry quickly, and most of the hiking happens during the summer, so you want your socks to be durable. Adding a higher percentage of synthetics will achieve this job.
For example, I hiked 800 km/500 miles with my Silverlight hiking socks, which have only 53% merino wool within the fabric, and I didn’t develop a single blister, they dried very quickly and started to smell only after 3-4 days of hiking.
But there are other factors to consider for summer hiking socks as well. First of all, your socks should be marketed as lightweight, not midweight or heavyweight, which means that they’ll have a bit less padding and the sock will be thinner. It should also have some kind of breathability panels within the sock. And finally, you should consider getting no-show or ankle socks, not crew or knee-high.
How Much Merino Wool Should Be In Winter Hiking Socks
To keep your feet warm in the winter, you should get socks with 50-75% merino wool content. This will make the sock a bit less durable and less resistant to water, but it will improve its breathability, thermoregulation, insulation, and odor resistance, which is important if you’ll be hiking with insulated hiking boots.
You should ideally go with a crew or knee-high sock, and it should be marketed as a heavyweight or midweight sock.
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What Other Materials Should Be In Hiking Socks In Addition To Merino Wool
First of all, the sock should be mixed with a synthetic fabric, to make it more durable and water-resistant. Popular choices include nylon, polyester, polypropylene, and acrylic. Of the three, acrylic is the warmest, but least durable. Nylon is the strongest and most odor-resistant but soaks up more water than polyester.
Merino wool and synthetics usually aren’t too stretchy, so to achieve a good fit, the sock needs to be more elastic. This is usually done with elastane, spandex, or Lycra. Generally, all three materials are pretty much identical, so it doesn’t matter which one the manufacturer has chosen.
And lastly, some manufacturers also add silver yarn to the fabric to make it more odor-resistant and improve its blister resistance. That’s because bacteria make the sock start to smell quicker and speed up the blister formation process, and silver actively kills bacteria. The effect of silver is minor though, so if the hiking sock doesn’t have it, it’s not a big deal.
It’s Also Important To Choose Good-Quality Merino Wool
The thing that makes merino wool perform better is the thin diameter of the merino wool fibers. It makes the fabric keep cool when used in the summer and warm in winter, improves odor-resistance and water resistance, and makes it feel softer on the skin.
The thickness of merino wool fibers is determined by where the sheep were grown and how old it was. So merino wool harvested from some sheep may be worse than others, and the thinner the fiber – the more the wool usually costs, even though all of them can be sold as “merino wool”.
Good manufacturers usually use better-quality merino wool, so the cheap merino wool socks that you’ll find on Amazon most likely won’t perform nearly as well as more expensive ones. I’ve found that you can find good quality socks in the 20-40$ range. Brands that use good quality merino wool include Darn Tough, Silverlight, Smartwool, Farm to Feet, Danish Endurance, Injinji, and others.
Frequently Asked Questions
Which are the best merino wool socks?
It’s hard for me to say which merino wool socks are the best ones, but my personal favorite is the Silverlight hiking socks. They contain 53% merino wool, 40% nylon, 5% silver, and 2% spandex. I haven’t had a single blister since I started using these socks, they’re super comfortable and breathable, and I’ve been using them for almost two years and they’re still going strong. However, most socks from Darn Tough and Smartwool are also really good.
Why are merino wool socks so expensive?
Merino wool is more expensive because it’s harvested from a single breed of sheep, which can only be grown in certain parts of the world, usually Australia and New Zealand. For outdoor apparel specifically, merino wool is usually the best choice, so there’s also a lot of demand for merino wool, which drives up its cost.
Are merino wool socks worth it?
From my own experience, merino wool socks are definitely worth it if you’ll be hiking for multiple days. With other socks, I used to get blisters. When I switched to merino wool socks, I stopped having them.
Merino wool works so great because it absorbs the sweat from your feet and gradually moves it to the outer layers of the sock to evaporate it. This makes the sock stay dry even during active, tough hiking, which in turn reduces the chances of blister formation.
It’s also great because of its ability to absorb bacteria and water. It can store up to 1/3 of its weight in water, while still feeling good on your skin. And by trapping the bacteria inside the fabric, where they’re unlikely to continue to grow, the socks also need to be washed less regularly.
Read Next: How Much Should Hiking Socks Weigh
Are merino wool socks good for sweaty feet?
Merino wool socks work particularly well for people with sweaty feet. If your feet tend to sweat a lot, choose a sock with a higher merino wool content, somewhere between 50-75%, even for summer hiking. This will allow the sock to stay dry even when your feet sweat. And if you get two pairs and switch between them in the afternoon, your feet should stay dry during the whole day.