Superwash is not the only easy-care option
Untreated wool is susceptible to felting. Most animal fibers have scales
along their length and when washed in a washing machine, the heat,
agitation and rapid cooling at the rinse stage combine to give ideal
conditions for the scales to interlock, causing the fabric to felt
A garment made from a superwash wool, on the other hand, can often cope
with being thrown in the machine as part of the normal wash. Most superwash
yarns are created by eroding the scales with acids and then coating the
fibers with a synthetic resin. The coating smooths and softens the fibers,
preventing felting during the washing process.
However, there are downsides associated with superwash yarns:
Environmental risks - Hazardous chemicals and large quantities of water
are required, and waste water leaving the manufacturing plant can be
Fabric stretching - The smooth nature of the fibers means the yarn has
less resilience: the finished fabric of my superwash swatches grew
widthways and lengthways after washing.
Lack of diversity - Few single-breed yarns are available in the
quantities required for superwash processing. Many wonderful wool and
alpaca yarns will be overlooked by a knitter or crocheter concerned about
venturing beyond superwash.
So do we have to choose between practicality and our environment? Is
there a way to avoid dripping a sinkful of water over the kitchen floor
while not risking spontaneous shrinkage of your precious handknit?
To find out what different fibers can withstand during washing, I made a
number of swatches in a variety of yarns: generic and single-breed
untreated wool; superwash wool; alpaca; llama; and the synthetics viscose
and acrylic. Then I put them through progressively more demanding washing
cycles. The results are shown below.
The 30° Synthetics washing program, even with its reduced spin,
involved too much agitation for the untreated wools: all the non-superwash
animal fiber swatches felted. Below is the Bergere de France Pur Merinos
Francais (100% untreated Merino wool) before and after the 30°
However the Wool / Hand Wash cycle on my washing machine is as gentle as
washing by hand. All the hand-wash-only swatches were improved by the
washing process, just as they would be by hand washing in a sink. Of course
not all machines are the same as mine (for the record I have a
front-loading machine, I used wool wash and no fabric conditioner) so
experiment with swatches rather than garments!
I have never previously felt confident putting a handknit in the washing
machine but seeing how well the swatches fared, I put two hand-wash jumpers
through the gentle cycle. They came out perfectly.
Knowing how to care for a range of yarns means you can choose the right
yarn for your circumstances. For example I wouldn't consider giving a
hand-wash garment to a new mum - delicate care of a handknit is not on her
list of priorities! If you can't be sure that a garment will be put on a
gentle cycle in a washing machine, then superwash or acrylic are the
If you can get hold of it (and afford it!) the
Rosy Green Wools gain
machine-washability via a Global Organic Textile Standard-certified
process that doesn't involve waste-water chemicals or a resin coating.
Woolful have also provided this list of superwash alternatives.
But if you can take just a little care with your washing machine settings
then the whole world of untreated animal fiber is open to you.
P.S. If you ever do find yourself with a felted jumper,
here is a great way to upcycle it!