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Wool is such a great fiber. It insulates us from the cold in winter and the heat in summer, it is resilient and can be stretched out and will spring right back into shape, it takes dyes readily yet comes in many gorgeous natural colors, it renews yearly, and different breeds offer us a range of fiber that can be soft and cushy for next to the skin wear, lustrous and silky for great drape in shawls,and long and durable for excellent rugs, upholstery, slippers and boots!

The one downside wool has for some knitters is that it felts! Of course, we love it for that too! But not if you want to knit for a child, a new mother or perhaps for some college age kids who you think may not take to hand wash anything while away at school!

So machine washable wools are a great category for knitters in providing us an option for knitting a machine washable garment in a natural fiber, but given the changes to our detergents, our washing machines, and the processes for making a wool machine washable, I wanted to share with you some points to consider when choosing a machine washable wool for your next project.


Machine washable 100% wools have been around for many years now, but much has changed in their processing in the last decade.

And much has changed in our detergents and washing machines too!

Here are some new things that I recently discovered about new ways of making wools "machine washable, the impact that energy efficient washing machines have on machine washable wools and how the new formulations of detergents may impact our care of machine washable wools.

This investigation came about because I had feedback from a customer who worked with the Cascade 220 Superwash and had not been happy with how it washed up. I saw a sweater she was talking about and it had quite a bit of pilling after just 1 wash, and I didn't think that was acceptable.

Since a less than desirable outcome such as this can be the result of EITHER or BOTH the way the wool was been rendered "superwashed" AND the way knitters care for/wash machine washable wools, I thought I'd share some of what I learned here so that you can avoid having a similarly disappointing outcome.


Firstly, there are several different ways that a mill can make a wool machine washable and the approach used can affect how the wool washes and wears.

Secondly, how the finished garment is washed can affect how it wears/pills. This is important because even tho' a wool may be labelled "machine washable" doesn't necessarily mean you can expect it to hold up to very harsh detergents, really hot water, low water level, or being washed in with heavy items such as jeans or towels


So the first set of suggestions I can make if you are currently knitting a project with a machine wash wool are:

1) be sure to wash on a high water level. Since many of the newer energy efficient machines use a very low water level, you are apt to get too much friction of the knitted garment. So if you can adjust your machine settings for a higher water level, that will reduce pilling.

2) do not wash your knitted garment in with other heavy items..... wash it alone or with light weight items to reduce the friction it is exposed to. No jeans, towels, etc!

3) do not use your regular laundry detergent! Even tho' washes like Eucalan, Soak, Kookaburra are sold here/advertised for your "handwashables", you should still use them in your machine with your machine washable wools. Why? Because the detergent you use for your regular laundry is likely to have enzymes in it. When the detergent industry did away with phosphates (a good thing since it is better for our environment not to have them flowing into our streams and lakes) the detergent companies started adding enzymes to their formulas to help boost the washing power we lost with the removal of phosphates. The enzymes in your regular laundry detergent can eat away at the coating/resin on the machine washable wools (read more about the coating/resin below). This, in turn, makes the wool more apt to pill.

4) just be aware that most of the machine washable wools indicate on the label what temperature (usually expressed in centigrade) water they are recommended for and some of you may have your water temperature set much higher than that. So check your label and adjust your machine's water temperature accordingly since really hot water can affect the wear of the machine washable wools as well.

So, even with machine washable wool garments you may want to make a few adjustments to your usual washing behaviors.

One more suggestion before I review a few things about how the mills make yarns machine washable ...

5) while I usually recommend laying a wool garment flat to dry, every yarn distributor/mill I spoke with regarding machine washable wools said that (as long as the label says you can machine dry them) you should machine dry the garment after washing! This is because you'll find that machine washable wool stretches out in the wash and you need the dryer to get it back to shape.


So, now a couple points as to how wool is made "machine washable" if you're curious about why some machine washable wools wear better or feel better than others...:...

Each of the various "superwash" processes aim to "remove" or "nullify" the scales, which are what causes wool to shrink in the wash (if you looked at a lock of wool under the microscope it would look like a reptile or fish because it has scales).

Scales can be removed chemically, or rendered "inert" physically or enzymatically.

The removal of the scales chemically (usually with some form of chlorine) leaves little "pits" in the wool shaft. Therefore wool treated with chlorine is often then coated with a "resin" or "inert polymer" to smooth out the "pits".

Without boring you about the various methods for using chlorine to chemically remove the scales (Hercosett, Kroy, Dylan etc), just know that there are generally 4 steps involved and each step can affect the resulting wool's feel , durability and cost:

chlorine treatment - how much time the fiber is exposed to the wool?

neutralization -whether sodium carbonate or sodium bisulphate (more expensive but yielding a fiber with better affinity for the resin) is used?

rinse - is the ph back to a neutral range?

coating -cationic polyamide, epoxy, glycerin, etc used?

Given the variables in the processes, it is not surprising that different brands of machine washable wools feel quite differently and may wash and wear differently.

So if you have experienced a bit of pilling with any machine washable wools recently, try the 5 remedies I suggested above. And don't equate all machine washable wools, since the processing can make quite a bit of difference.

And given the changes in our laundry detergents over the course of the last decade , as well as in our washing machines, it is not surprising that we may need to be aware of and make some small adjustments to how we wash machine washables going forward.


Speaking of moving forward, there are more advances being made in the processing of machine washable wools. They are newer and a bit more expensive,


there are mills developing new ways of physically and enzymatically dealing with the scales to make a wool washable without having to apply a resin to "fill the pits".


These are often referred to as " Eco-wash" wools.

(This is a trademarked name for a particular process that is being developed in the US) 

The Eco-wash process keeps the scales on the wool, and treats the yarns with an organic enzyme that renders it washable.

The Eco-wash yarns are springy and smooth and show excellent stitch definition. 

One of the new spring yarns I have coming is Swan Island's new Eco Sport.This sport weight 100% wool has been treated in this "Eco-Wash" way and this yarn has demonstrated great results in both washability and wear.

And I'd like to debunk a myth that is circulating around about Superwashing. Namely that all superwash mills are in China.

That's not true. Many are and, frankly, probably most of the commercial superwash yarns you'll find on the market are superwashed in China. If that is a concern for you, then focus on the Eco Wash by Swan Island I mentioned above or...

Plymouth's Superwash Merino Worsted is milled and superwashed in Peru. This yarn uses the Hercoseett process and it wears well and still exhibits much of it's natural spring.

I'm still waiting to hear about the Bliss and Sublime machine washables.