Unraveling the Myth of Sock Yarn: Finding the Perfect Wool for Sustainable Socks

Unraveling the Myth of Sock Yarn: Finding the Perfect Wool for Sustainable Socks

When you walk into almost any yarn shop and ask for sock yarn, the salesperson will likely show you to the section of fingering weight yarn made up of blends of superwash Merino and nylon. Usually, the ratio is 75 or 80% SW Merino and 20 or 25% nylon. The claim is that this yarn is both machine washable (because you need to be able to wash your socks!) and has added strength from the nylon. But is this really the best yarn for socks? Let’s explore what makes a good sock yarn and discover some other options for your next pair of socks!


What Makes a Good Sock?

Depending on how much time you spend on your feet and what kind of shoes you wear, your socks can be subject to pretty tough wear. They rub against the fabric of our shoes or carpets and floors, they absorb a lot of sweat, and they have the entire weight of our bodies pressing down on them as we walk. So a good sock needs to be durable as well as comfortable. The skin of our feet is generally less sensitive than that of the rest of our bodies, but you don’t want to have scratchy or uncomfortable fabric for your socks. So while sock yarn doesn’t have to be as soft as something we’d wear around our necks or wrists, we still want it to be comfortable. Socks also need to be elastic. They have to stretch over your heel but then fit snugly after stretching. No one wants to wear floppy or loose socks that bunch up inside shoes. And because our socks are often trapped in our shoes all day, they need to be able to wick moisture away from our sweaty skin to keep our feet dry and comfortable.  The best sock yarn is one that strikes a balance between durability, softness, and elasticity. So what yarn characteristics should we be looking at to find that balance?

The Four Most Important Factors to Consider for Sock Yarn


While “ply” is used to describe the thickness of yarn in Europe and the UK, in this context we’re talking about the number of strands that make up a yarn. Some yarns are single ply, meaning there is only one strand, which often results in fluffy, more delicate yarn that is prone to breaking and pilling. A multi-ply yarn has several strands that are twisted around each other in the spinning process, resulting in a stronger, often sleeker yarn. For socks, I like to use 4-ply yarn, though I have had success with 2 or 3-ply yarns as well. But avoid single-ply yarns for socks.


“Twist” in yarn refers to the way the strands are spun and the plies are twisted together. The direction is either “S” or “Z”, as the resulting yarn imitates the shape of those letters. Most commercial yarn is spun with a Z twist for single strands, and then plied with an S twist to create a balanced fiber. The act of knitting can add more twist (i.e., tighten the twist) or take away twist (i.e., untwist slightly). If you knit like most knitters in the West, with the right leg of each stitch at the front, then knitting a Z twist, S plied yarn will add twist. This is generally desirable, as it creates neat stitches and helps avoid splitting plies while knitting. In sock knitting, this is even more important, because an important factor in sock yarns is that it is high twist, meaning that the strands are tightly plied together. This creates a uniform, durable fabric that is more resistant to breaking or wearing through. Look for a high-twist, 4-ply yarn with a Z twist and S ply for the ideal socks.

Fiber Content:

Of course, one of the most important factors we look for in any yarn for any project is the fiber content. Among popular yarn fibers like wool, cotton, and acrylic, wool is generally considered the best for socks. It’s strong, soft, elastic, and excellent at moisture wicking and temperature regulation. However, not all wool is created equal. Different breeds of sheep produce wools with a variety of different characteristics. One important factor is the staple length. This refers to the average length of the fiber before it is spun. Breeds with short staple lengths, like Merino, tend to be softer and ideal for next-to-skin wear in sweaters and scarves. But because of its short staple length, it requires more twist to hold together when spun. Longwools like Blue-faced Leicester and Romney have a longer staple length and are thus sturdier yarns, as there are fewer weak points where the fiber might break. So while Merino might be soft and luxurious, it’s not as ideal for durable, long-lasting socks as a wool breed with a longer staple length. This is why Merino is often blended with nylon, to give it some extra strength. However, many sock blends contain cut nylon rather than monofilament nylon, which has more weak points where the fiber can break.

Superwash vs Non:

After a long day trapped in shoes and soaking up sweat, socks need a good wash. Most people prefer to just chuck them in a washing machine rather than wash by hand, and thus opt for superwash sock yarn that can handle the heat and agitation of a washer and dryer. But the superwash process doesn’t just make your socks machine washable. It actually strips the wool of many of its most beneficial properties. Wool fiber has scales that make it water-repellant, keeping the sheep dry in inclement weather. To create a washable yarn, the scales need to be removed so that they don’t lock together and felt in the wash. This removal process usually involves stripping the scales with chemicals and then filling in the empty spaces with a plastic polymer, or simply coating the scales in a thin layer of plastic so they can’t move. This process makes wool washable, yes, but it also makes it less durable and less able to absorb and wick away moisture, as well as reducing its ability to recover to its original form after stretching. All the properties that make wool ideal for socks are reduced when the yarn is superwash-treated. This is another reason nylon is added, because it helps superwash wools recover after stretching and adds a bit of durability. So while superwash wool is easier to deal with on laundry day, it’s not necessarily the best fiber for hard-wearing socks.


So What’s the Best Yarn for Socks?

Ultimately, this is a subjective question because it depends a lot on the knitter and the wearer. And other factors such as gauge and stitch pattern can affect the durability and elasticity of socks. But for me, the best sock yarn is a 100% non-superwash longwool. I personally prefer to use all-natural fibers and avoid synthetics to reduce the amount of plastic production and pollution in our world, and because a strong, non-superwash wool doesn’t need the help of nylon to be an ideal sock yarn.


Washing 100% Non-Superwash Wool Socks

I hand-wash my socks in batches each week by soaking them in a small bucket or in the bathroom sink with lukewarm water and some wool wash, giving them a little swish (but not too much agitation). Then I lay them on a drying rack to dry. It’s not much more trouble than putting them in the washing machine. Actually, it’s much less trouble for me, since I don’t have to go downstairs to the laundry room in the basement of my apartment building!


How to Handle Felting

My socks do felt a little bit at pressure points like heels, toes, and the balls of my feet, but that actually makes them stronger and less likely to wear out in the spots. I simply knit my socks a little longer in the foot to accommodate the slight shrinkage from that felting. Once those spots are felted, they won’t shrink anymore, so they fit perfectly after one or two wears.



In the end, choosing the best sock yarn will always be a personal choice, but I hope this article gave you some guidance on what characteristics to consider when shopping. I highly encourage you to try different yarns and see what works best for you! But don’t be afraid to use non-superwash and no-nylon wool for socks, and don’t let anyone tell you there’s only one type of “sock yarn”. Use whatever works best for you and have fun knitting!


If you’d like to try knitting a pair of socks with 100% wool, check out my 4-ply Highland Sock Sets, a high-twist Peruvian Highland (long) wool that I have naturally dyed with botanical dyes. You can also check out my best-selling sock pattern, the TAATTU Socks Formula, to knit custom-fit two-at-a-time, toe-up socks with any gauge. 

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