Merino wool in focus: benefits and drawbacks for outdoor enthusiasts

Merino wool is one of the most versatile materials in the outdoor world. It regulates body temperature, naturally inhibits odours and feels more comfortable against the skin than many synthetic fibres. But this natural material has its weaknesses too. We look at who merino is the right choice for, and where alternatives perform better.

Merino wool is more than a trend. Its range of properties makes it indispensable for outdoor enthusiasts. One of its greatest benefits is its excellent thermoregulation. The fine merino fibres can trap a large amount of air, creating an insulating layer. This means it keeps you comfortably warm in winter while also having a cooling effect when temperatures rise. This ability to regulate temperature is particularly valuable in changeable weather or during intense activity, as it helps keep the body at its optimum operating temperature. Another advantage is its moisture management. Merino fibres can absorb up to 35% of their own weight in moisture without feeling wet. This moisture is then slowly transported outwards, helping to keep the skin dry and prevent chilling, a key factor in avoiding colds. The wool's breathability also helps prevent uncomfortable heat build-up. Statistics show that fine 16.5-micron merino wool is among the softest types and can reach weights of up to 1,000 g/m² in high-quality blankets, underlining its insulating properties.

After an intense tour, synthetic clothing can quickly start to smell unpleasant. This is where merino wool reveals another strength: it is naturally odour-resistant and antibacterial. The surface of merino fibres is complex, making it harder for the bacteria responsible for unpleasant odours to attach and multiply. This means you can wear merino clothing for several days without it starting to smell, ideal for multi-day trekking trips or travelling light. This property also makes it interesting for allergy sufferers, as it reduces mite reproduction. Alongside its functionality, merino wool also stands out for its wearing comfort. Unlike conventional wool, merino wool does not itch. Its fibres are so fine and soft, often under 19 microns, that they feel gentle against the skin. This makes it the perfect choice for underwear and baselayers worn directly next to the body. The wool's elasticity and shape retention also ensure that clothing keeps its fit and does not stretch out, even after frequent wear and washing. Many manufacturers, including Engel and Woolville, emphasise the ‘highest quality’ of the temperature-regulating and odour-resistant properties of their merino products.

Despite its many advantages, merino wool also has a few aspects to consider before buying. One of the most obvious drawbacks is its higher price compared with synthetic alternatives. The complex sourcing and processing of the fine fibres, along with the high animal welfare standards that many manufacturers now meet, are reflected in the price. For many people, however, the investment is worthwhile because of its durability and functionality. Another consideration is the care required. Merino wool is more delicate than synthetic fibres. It is sensitive to high temperatures, heavy friction and certain detergents. Incorrect care can cause shrinking, felting or fibre damage. Although modern merino products are often machine washable, they still need more attention when being cared for. A knitting expert from JoelJoel, for example, warns that knitting too tightly or using needles that are too small can make merino wool feel ‘like a board’ and cause it to lose its fluffiness. This shows how important proper handling is for preserving the material's softness and quality.

Merino wool is resilient, but it is not indestructible. Compared with robust synthetic fibres, it is less resistant to wear and abrasion. In high-stress areas such as beneath rucksack straps or under the arms, pilling or thin patches can develop more quickly. To counter this drawback, many manufacturers use material blends. Adding synthetic fibres such as nylon or Tencel increases durability without overly compromising merino wool's positive properties. These hybrid products combine the best of both worlds: the comfort and thermoregulation of wool with the strength and durability of synthetic fibres. In addition, sourcing the material can remain controversial in some circles despite high animal welfare standards such as mulesing-free production. Recycled wool is therefore becoming increasingly popular as a more sustainable alternative. Although merino wool is very skin-friendly for most people, some allergy sufferers are generally sensitive to wool and need to choose alternatives.