As winter sets in, many of us are turning to our cosy jumpers, snug base layers and anything else that can take the bite out of cold mornings. That is where merino wool shines.
It is warm, comfortable and surprisingly adaptable , making it a smart choice for days when the weather can't quite make up its mind.
But exactly why is it such a good material?
What is merino wool?
Wool begins as a natural fibre grown on sheep and collected by shearing. After that, it is cleaned, sorted and spun into yarn before becoming fabric. The quality of the final product depends heavily on the quality of the fibres themselves.
Merino wool comes from Merino sheep, a breed known for producing very fine wool fibres. The Spanish Merino is especially important because it is described as the founder of the other Merino and Merino-derived breeds worldwide. It dates back to Roman times on the Iberian peninsula.
That long history of breeding for fine wool is part of why merino remains so highly valued today. In simple terms, merino is not just "wool"; it is a type of wool that has been selected over time for softness, quality and usefulness in clothing.
Research on Spanish Merino shows there are several features that play a role in how the wool feels and performs. These include the diameter, length and curvature of the wool fibres.
What makes merino different from many other types of wool is the fineness of its fibres . Finer wool fibres are closely linked with comfort and softness, while the opposite is true for thicker wool fibres.
However, wool quality varies even within Merino sheep, which means some merino is finer than others. Merino wool is therefore not one fixed thing, but a whole family of wool types with different levels of softness and performance.
Another reason merino is so loved is that it tends to smell less than many other materials, including cotton. Wool does not kill bacteria outright , but it does affect how bacteria sit on the fibre surface.
In other words, wool changes the conditions that bacteria prefer. That helps explain why merino often stays fresher for longer. Odour usually develops when sweat, moisture and microbes work together - and wool helps slow that whole process down.
Not just for winter
Merino is not only a winter fabric. It helps regulate the body's microclimate , which means it can support comfort in warm conditions as well as cold ones.
Merino can absorb and release moisture in a way that helps reduce the sticky feeling many people get when they sweat. It also helps the body handle shifting temperatures during the day, which is especially handy when the weather is changeable or you are moving around a lot.
So merino works in summer because it helps the body stay drier and more balanced .
Not a flawless material
Of course, merino wool is not flawless. It can be more expensive than cotton or many synthetic fabrics and it often needs a little more care when washing. It may also be less tough than some hard-wearing synthetic materials.
And because it comes from sheep, some people may prefer plant-based or non-animal fibres for ethical reasons. So while merino is wonderfully effective, it is not the right choice for every person, every budget or every purpose.
Merino can still feel itchy because itchiness is not only about whether a fibre is "soft" in general, but about how it behaves against the skin. A prickling sensation happens when tiny fibre ends stick out from the fabric and press into the skin with enough force . So even fine wool such as merino can feel irritating if the garment structure leaves more of those ends exposed, or if the fabric rubs a sensitive area.
In other words, merino is usually gentler than ordinary wool, but comfort still depends on the exact fibre thickness, how the yarn or knit is made, and how sensitive the wearer's skin is.
Caring for merino wool
Even so, merino is fairly easy to care for if it is treated gently. It does not need washing after every wear because it naturally resists odour, so airing it out between uses is usually enough.
When it does need cleaning, a cool or lukewarm wash with a mild wool detergent is safest, followed by flat drying away from direct heat. It is best to avoid wringing, rubbing or tumble drying, as these can cause shrinking, stretching or damage to the fibres.
Merino remains popular because it strikes a lovely balance. It is warm without feeling bulky, soft without being fussy and useful in both chilly and mild conditions. And with its odour resistance and all-day comfort, it is easy to see why merino keeps winning people over.
Carolina Quintero Rodriguez is a member of Standards Australia and Secretary of the Textile Institute Australia.
