Should Knitters Avoid Superwash Wool?

Every now and then I learn something that seems so obvious I wonder why I've never realised it before. The latest occurrence was when I read Kate Davies' blog post featuring an interview with Yasmin Harper, owner of the French knitting store Laine des Iles (roughly translated as Island Wool).

In the interview, talking about the wool she stocks, she says:

"I am certainly not in favour of superwash yarns. I find it quite frustrating that there is no requirement to label a yarn as super wash or for manufacturers to explain on their labelling what this means (essentially, that it is plastic coated). I still find a lot of customers who react with surprise when I tell them this - they just don't know."

Superwash image courtesy of Patons

I didn't know either. I knew that superwash wool tended to be softer and machine-washable, but I never gave a thought as to WHY.

So I did some online research to find out what exactly goes on to turn wool into superwash. This is what I found from The Spruce Crafts:

"Superwash wool can be made using an acid bath that removes the scales from the fibre, or it can be made by coating the fibre with a polymer that keeps the scales from being able to join together and cause shrinkage."

The American website Knitting The Natural Way says that chlorine is used in acid baths and because of that the waste water is not accepted by the majority of water treatment facilities in the USA. So where does it go? It's sent to be processed in other countries including China and the UK. Lucky us taking other countries' toxic waste.

Quite a lot of wool brands sell superwash yarn whether it's labelled as such or not. Clues that your wool may be superwash are that it feels slicker and denser than regular wool and looks slightly shiny.

If you're choosing to knit with wool because it's a natural fibre and you've purposefully avoided man-made yarns such as acrylic and polyester due to them being produced from oil, then buying superwash flushes those environmental principles straight down the loo.

I asked Jess James-Thomson, prolific knitter, yarn dyer and owner of Edinburgh yarn store Ginger Twist Studio, for her opinion on the matter. She says prefers to go for non-superwash wool whenever possible because it is environmentally-friendly and she likes the way it takes the dye.

Splendor 4ply image courtesy of Ginger Twist Studio

Fans of superwash wool say that it's easier to wash and is softer against the skin, particularly for babies. Arguments against this are that superwash garments can stretch when machine-washed. Also there are lots of non-superwash yarns on the market tailored for babies, including Debbie Bliss Eco Baby and Sublime Baby Cashmere.

Sock knitters may like superwash wool so the socks can be easily washed to get rid of foot pongs, but again there are non-superwash wool yarns on the market, a leader being West Yorkshire Spinners' Signature 4ply.

To those who say non-superwash wool is itchy, think of the multitude of wool and fibre blends to choose from.  James-Thomson says that "my Splendor 4ply is a mix of non-superwash merino and silk, and I would challenge anyone to find that itchy!"

There is an alternative to superwash but few wool producers use it, as Yasmin Harper points out on her own blog.  "A new superwash treatment called EXP that has been developed by Schoeller Wool in Germany - a GOTS certified treatment that does not involve chlorine washing, and only minimal amounts of ecological polymer. However it is currently used by only a very small number of knitting yarn companies."

If you want to avoid superwash and aren't sure if your chosen wool has been treated then ask the yarn retailer. If they don't know then don't buy it. The more people who raise the issue at their local yarn store the better, as to stay competitive yarn companies have to produce what the public want to buy.

Now what else don't I know that's blatantly obvious??