Darn Tough logo among Merino Wool fibers from making merino wool socksDarn Tough logo among Merino Wool fibers from making merino wool socks

Merino Wool

Naturally evolved over thousands of years, we choose Merino Wool for our socks because it’s wildly resilient and incredibly versatile. More often than not, it’s not wool you're allergic to, it’s the kind of wool you’re wearing. Merino Wool is soft and comfortable.

What Is Merino Wool?

Merino Wool is the world’s most versatile performance fabric. It comes from high-elevation areas in New Zealand and Australia where Merino sheep run wild. The Merino breed’s wool is revered for its durability and moisture-wicking capabilities. Under a microscope, its fibers measure half as thick as human hairs but are twice as resilient, capable of being twisted up to 20,000 times without breaking. 

The inherent power of Merino Wool is its ability to stretch, thanks to natural crimps in its fibers. These creases, or folds, coil together to create Merino Wool’s elastic-like core, giving it a reflexive memory that snaps back into place during and after rigorous activity. Compared to other sock materials, we choose Merino Wool because its wildly durable, temperature regulating, and silky smooth on your skin. 

Infographic showing anatomy of a merino fiber, the crimp, scales, outer cuticle, and inner cortex

The Benefits of Merino Wool

Merino Wool is a natural fiber that we use to knit hiking socks and other activity-specific socks. The benefits of Merino Wool are that its naturally odor resistant, moisture wicking, and thermoregulating. Unlike cotton socks, wearing Merino Wool is better for foot health because it combats odors and insulates even after it gets wet. And because life just wouldn’t be the same without it. 

Merino Wool is moisture wicking, making it the best material for socks

Moisture Wicking

As your body heats, Merino Wool absorbs moisture before it turns into sweat on your skin, and releases it, leaving you dry. In reverse, outside moisture is captured before it touches your skin. Meanwhile, cotton is like a sponge.

Merino wool socks are thermoregulating


There is a natural crimp in wool fiber that provides pockets of insulation — holding and releasing heat dependent on what the body is doing. Think of it like an insulated mug that maintains cold or heat. Synthetics can mimic but not replicate this behavior.

Merino wool socks are odor resistant, making them the best wool socks

Odor Resistant

Odor resistance is unique to wool. The chemical structure stops sweat and bacteria build-up. So go ahead and take a sniff. It's not impossible to stink up, but it naturally repels odor to the point you can wear them for multiple days before offending.

A close up look at merino wool yarn being turned into a sock on our knitting machines

We Only Use Three Ingredients in Our Socks

Merino Wool, Nylon, and Lycra® Spandex are the only yarns we knit into our socks. A pure Merino Wool sock would not have the elasticity to hold its fit, and Nylon strengthens wear zones. The list is simple, but it’s how we do it 
that knits a longer lasting sock.

Some Instincts Aren't Natural

There are more than a few misconceptions about wool, or at least Merino Wool.

Good news - merino wool socks are not itchy

Not Too Itchy

Correct, some wool is rough to the touch, but Merino is silky smooth. Under a microscope, the fiber has a longer, scale-like appearance for a fine, smooth feel.

Merino wool keeps you warm without unnecessary bulk, which is why it's the best for socks

Not Bulky

Our running and casual socks, for example, are incredibly thin. Merino Wool yarn is no thick strand you'd find in the crochet basket. You'd likely call it a thread.

Merino wool socks aren't just for cold weather - they're great in hot weather too

Not Just for Cold

The thermoregulating properties of Merino Wool will surprise you. Our heavyweight socks contain the most Merino Wool content and can be quite pleasant on a hot day.


While we knit, finish, and package all our socks in Vermont, our materials come from all over the globe – Merino Wool primarily from Australia, South Africa, and Patagonia. For whatever reason (it’s the environmental conditions) these sheep, with their ability to thrive in unforgiving climates, are still the best for sourcing quality materials.

A sheep standing on a globe to illustrate how we source our merino wool
Rows of Merino Wool cones at the Mill where we knit our merino wool socks

Responsible Wool Standard

We prioritize using Merino Wool exclusively from sheep that haven't been exposed to mulesing. In 2019, we made a commitment to support the Responsible Wool Standard (RWS) and shift 100% of our wool supply to RWS-certified Merino Wool. 

"Sheep have been running around mountains in wool for thousands of years."

Ric Cabot
President & CEO

Merino Wool FAQs

Merino Wool is incredibly soft and never itchy. Merino fibers are 1/3 the diameter of a human hair, making them more flexible and supple. So, when pressed against your skin, they’ll bend to provide a delightfully soft touch rather than being itchy and irritating.

Merino Wool fibers come from the fleece of Merino sheep, a breed known for their very fine, soft wool. It’s the world’s finest wool and revered for its inherent qualities, including durability. After being sheared and cleaned, Merino Wool is then spun into yarn and prepared for knitting.  

Merino Wool is perfect for summer, helping keep your feet dry and sweat-free on even the hottest days. It’s one of the most comfortable materials to wear in the summer because it’s breathable and moisture wicking. Plus, it’s also thermoregulating so your body doesn’t overheat. 

Merino Wool is great for winter because it helps keep your feet dry and regulates body temperature. Its fibers are made up of little crimps and bends that trap air and provide insulation for your feet, making it ideal for cold days and even colder nights.

It’s worth investing in a good pair of Merino Wool socks if you value fresh feet. Darn Tough Merino Wool socks hold their value and are Guaranteed for Life. So, if you buy one pair and they rip, tear, or puncture, we’ll replace them with a brand-new pair at no additional cost. 

Merino Wool’s natural qualities – moisture-wicking, thermoregulating, and odor-resistant – make it the best fabric for hiking. It helps prevent blisters in hiking boots and dries quickly after getting wet. It’s also exceptionally breathable and durable for hiking through rugged terrain.  

We combine Merino Wool with Nylon and Lycra Spandex to create a resilient performance fabric that lasts forever. Backed by our Unconditional Lifetime Guarantee, Darn Tough Merino Wool socks offer long-lasting durability that you can trust for prolonged hours on your feet. 

Merino Wool is moisture wicking and naturally pulls perspiration away from your skin when your feet start sweating. It maintains its ability to insulate and keep your feet warm even after it gets wet, making it ideal for managing sweat and regulating body temperature. 

The benefit of wearing Merino Wool is that it helps keep your feet dry and warm even after it gets wet. Merino Wool can absorb up to 30% of its weight in moisture without losing its ability to insulate. And after absorbing that much of its weight in water, it still doesn’t even feel like it’s wet.

Not all Merino Wool is the same. Depending on the diameter of its fibers, some Merino Wool is softer than others. At Darn Tough, we utilize the finest, highest-quality Merino Wool with varying weights and diameters for a next-to-skin feel that’s exceptionally comfortable.