What Is Superwash Wool?

A few weeks ago, I wrote about whether wool is a sustainable material to craft with and I deliberately didn’t go into superwash wool in that post, as I felt it needed a separate explanation. So here we are!

How is superwash wool different to regular wool?

Superwash wool is (typically) sheep’s wool which has been chemically treated to make it machine washable. I say typically as I’ve not come across any other animal wool which has been superwash treated, but that doesn’t mean that it doesn’t exist. It’s able to withstand being washed at temperatures up to 40ºC and is therefore (apparently) resistant to shrinking. A side effect of the superwash treatment is that it affects how the wool takes up and retains dyes, making it a popular base for super vibrant shades. Widely used by everyone from major yarn brands to indie dyers, it’s marketed as being simpler to care for, therefore making your life easier.

Superwash wool is a popular base for yarns, but it's not particularly environmentally friendly
Superwash wool is a popular base for yarns, but it’s not particularly environmentally friendly

As a result, many crafters don’t think too much about what superwash wool actually is. I’ve fallen into this trap too – back before I knew anything about yarn, I thought superwash wool would be preferable because it would be easier to care for. Some yarn companies and spinning mills have even found that customer demand is much higher for superwash wool, so most of their products use it as a base.

According to Lion Brand Yarns, there are two distinct processes which wool may go through during its superwash treatment: an acid bath or receiving a polymer coating (sometimes both). The reason for this is to prevent wool from sticking to itself – in short, wool is a scaly fibre which is easily entangled with itself. Consciously Crochet has explained how and why this occurs brilliantly.

What’s wrong with superwash treatments?

The superwash treatment uses both hazadous chemicals and lots of water, so it’s not particularly brilliant for the environment – or the people handling the chemicals and doing the treatments.

There is also, still, the possibility of damaging the polymer coatings and ruining your makes – and this can occur even if you keep to the washing instructions. I recently wrote about how to unshrink a woollen jumper and the jumper in question was knitted from superwash wool I’d chosen myself (again, before I really knew anything about yarn, but I know it was superwash). Even though I was always sure to wash it at 30ºC and under (it said 40ºC on the label) it still shrank.

Some say the superwash treatment reduces the wool’s insulating properties and microbial resistance, alongside its reduced ability to handle moisture content. So it seems that while ease of care and vibrancy of dyes are useful pluses, you lose some of the main features which make wool preferable to synthetic materials like acrylic.

It’s of course a personal choice to use superwash wool – you might be making something for another person and maybe don’t want to risk them not following the washing instructions, or perhaps making an item like socks which are likely to need washing often – but it’s also made slightly more difficult by the fact that it’s become so popular it can be difficult to find regular wool at times. As many more of us are becoming more aware of environmental impacts however (and several of us enjoy the experimental madness that is natural dyeing which is best done with locally available dyes and untreated fibres), I hope things will start to even out. Ultimately, if you can’t quite bring yourself to use superwash wool, it’s probably best to use untreated wool or another washable alternative, like cotton or perhaps tencel.

There are times where you might choose to use superwash wool, or perhaps choose to swap for another washable alternative
There are times where you might choose to use superwash wool, or perhaps choose to swap for another washable alternative

Despite the modern trend for convenience, there’s many people out there surviving just fine without washing machines, tumble dryers and all the mod-cons lots of folk have come to rely on (if you don’t believe me, check out the Tiny House movement, most tiny houses barely have space for a washing machine!) Handwashing clothes isn’t as difficult or as time consuming as a lot of people think – and when it comes to woollen items, it’s best to spot clean them anyway, only washing them when they really, absolutely need a complete wash.

Superwash and washable – what’s the difference?

Not all “washable” wools are superwash treated, as the process is patented. Check the label and item description carefully – if it’s superwash treated, it will say, if not it should say “washable”. If you aren’t sure, ask – most dyers and yarn companies shouldn’t mind answering such a question.

There are treatments to make wool washable without all the damaging chemicals, and any brands wanting to promote their sustainable credentials should be shouting from the rooftops that their washable wools are using these environmentally friendly treatments. Generally, if the company is GOTS (Global Organic Textile Standard) or OEKO-TEX certified, then they’re likely using a more environmentally friendly treatment, as both of these standards have strict requirements about environmental pollution and hazadous chemicals. It’s still a bit of a minefield to work out as a consumer though, so again, if you aren’t sure, ask. The main reason that superwash wool is so widely available is consumer demand, so if we as consumers start to demand more responsible, sustainable alternatives, yarn companies and spinning mills will respond.