What does superwash mean?

Superwash is a treatment applied to wool fibers that makes them more resistant to shrinking and changes the dye absorbability. We are very particular about where our wool is superwash treated, but this is not true of all suppliers. We are proud that, unlike our main competitor, our superwash wool is treated in Europe and not China.

In the 1980’s superwash treatment had a bad reputation because in some countries the effluent was polluted and not recycled. This has, however, changed dramatically as the EU enforced very strict laws and any by-products must now be removed before water is discharged into the water systems.

The mill where we get our Merino processed is accredited with the EU Flower and OEKO-TEX® 100 schemes and runs a state-of-the-art effluent treatment plant. This means that the water is recycled and when discharged, it is cleaner than drinking water you get from the tap.

Jeni has personally been to visit the superwash treatment plant in the UK that processes our Bluefaced Leicester wool. They employ the most up-to-date superwash techniques and are always trialling new ideas.

So what does the process involve? Firstly, the wool is treated with chlorine to dull the edges of the scales of the wool. This reduces the ability of the scales to stick to each other and therefore reduces felting. Secondly, a resin is applied and this creates a microscopic, web-like structure permanently bonded to the wool. This smooths the scales, improving the handle and preventing felting, whilst maintaining the dyeability.

Recent studies have shown that the type of superwash treatment we use biodegrades very quickly in compost and marine environments. This means that they leave no residue, unlike other superwash treatments. Some other shrink-resistant treatments can inhibit the dyeability of the wool which is why they are not suitable for our yarns. 

On balance we like superwash yarns because they make wool more accessible to people who would not be able to hand wash items on a regular basis. They have good longevity, but biodegrade rapidly when composted.