Deborah Robson Talks Washing Wool, Win Unicorn Fibre Wash

Guest star Deborah Robson visited the set of Knitting Daily TV for Series 800 and brought her expertise to the screen. Filming three segments, Deborah talked caring for fiber, avoiding yarn pilling, and dove into yak fibers. You can see all of Deb's videos on Here's one from episode 804:

Washing and caring for your fiber can make all the difference in the lifetime of your work. To celebrate our 100th episode, Unicorn Fibre has agreed to give one lucky winner a set of washing, rinsing, and scouring products to prolong the life of your knitwear. Simply comment on this blog for your chance to win, details below

Here's Deborah to talk more about washing fiber:

Washing wool 
I love washing wool, whether it's fleece I'm going to spin, a newly finished garment whose beauty will be revealed after its first bath-and-blocking, or a loyal garment that has earned refreshment.

Freshly shorn wool may be the most fun to wash, because of its dramatic transformation. The grease that coats the fibers when the sheep is using the fleece to keep herself warm through the winter is still soft, resilient, and relatively easy to remove. I think of the animal, freshly released from this seasonally necessary burden to enjoy the spring air (and to begin growing next winter's blanket), and I think of the fabrics I will make from her hand-me-downs to keep other beings cosy in the future.

Even long-stored fleece can be rewarding to put through the washing process, which releases it from a stiff accompaniment of old grease and dust. Although it's best to wash wool soon after shearing, in part because moths especially savor the "extras" that are removed when the fiber is cleaned, as long as you can keep pests away you can safely store wool for many years.

Here's Emma's fleece when she was done with it, on its first trip into the warm water that begins my washing process:

  • wool has ONLY been soaked in warm water
  • tray on right has been removed, after the first of
    two water soaks, from the center tray
  • the dark brown is water-soluble dirt and suint
  • END OF CYCLE after use of cleansing aid
  • tray on right has been removed, after its cleansing
    soaks, from the center tray
  • tray on left awaits draining










It's easy to imagine that she'd want to start over with fresh growth!

Emma is a Leicester Longwool sheep, a breed known for its long, shiny, strong fiber. The beauty of the wool becomes apparent after about two hours of soaking in a series of baths, beginning and ending with plain-water versions, and with two or three in the middle that are infused with a washing agent.

I've described the details of my washing process elsewhere. Today I want to talk briefly about the transition from dirty to clean, mostly for fleece but also for garments.

This image shows the raw, dirty wool on left and
clean wool on right (same fleece)

Washing or scouring?
Washing is what I just talked about. The process of cleaning raw wool is also sometimes called scouring, a term used in industry to include the removal of all contaminants from wool-scouring is "washing plus."

What might the contaminants in wool be? I say might because not every fleece will have all of these, and each fleece will have contaminants in differing types and proportions.

The big three, present to some extent in every fleece, are:

  • wool wax or wool grease
  • suint
  • dirt

Wool wax or grease is not water-soluble. It provides a protective coating, and, in general, the finer the wool the more grease it contains. It's the hardest of the three main contaminants to remove. That's the point for the sheep! It shouldn't be easy to remove!

Suint (think "sweat") is water-soluble-even in cold water. When we're washing wool, it's the easiest contaminant to get rid of.

Dirt is soil, and can be dust or mud. It can be sandy, or full of clay, or may correspond to any of the gardener's or farmer's other options, and it can be easy or hard to remove, although most of it isn't too bad. (Clay, of course, is most difficult, as it seems to be for growing plants where I live.)

Vegetable matter (or VM) is another contaminant that comes in many varieties. For hand processing, VM isn't, for the most part, removed during the washing sequence and its evaluation and management is a topic for another day. In industrial processing, treatment to remove VM occurs during the scouring sequence and involves a delicate sequence of chemical and mechanical maneuvers to get the plant material out without damaging the wool-a different topic for another day.

Some other contaminants-like dung tags, urine stains, marker dye, and insects-should have been removed before the fleece ever reached the washing or scouring stage.

What to use as a washing aid?
For the intermediate steps of cleaning wool, whether raw or spun or made into fabric, we have many choices in washing aids. I've used a number of them over the years. At this point, I have several criteria for the agent that I use. Oddly, they all start with E!

I want it to be effective, efficient to use, economical, and as environmentally benign as possible.

That means that I look for a washing assistant that

  • is concentrated so I don't need to use large quantities
  • creates minimal suds (which are hard to rinse out, wasting both time and water)
  • does not subject the wool to significant and potentially damaging pH shifts
  • works at moderate heat levels even for fine wools (in order to reduce the potential of fiber damage, and so I don't have to be boiling water or otherwise wasting energy)
  • cleans by bonding with the waxy or greasy particles, drawing them off the fiber and into the water so they can be rinsed away, instead of being knocked off through agitation (which can result in unintended felt, as well as more work for me)
  • does not involve enzymes (which continue to be chemically active even after they've been discarded) and
  • contains no ingredients classified as toxic.

knitted swatch of Leicester Longwool, commercially
spun yarn from the same flock that Emma is part of

I now use washing agents that are specially formulated for use with wool. I like Unicorn Power Scour for cleaning raw wool; Unicorn Fibre Wash for my yarns and finished products; and Unicorn Fibre Rinse as a final treatment in either case.

Dishwashing detergents and shampoos create annoying amounts of suds. I'd rather avoid the perfumes and colorants that many cosmetic products contain. Laundry detergents often contain brighteners, enzymes, and other ingredients I consider extraneous at best and damaging at worst. Some components of laundry detergents are actually designed to break down proteins (to get out stains like blood or egg), and animal-source natural fibers are also proteins! It is interesting to check these products' Material Safety Data Sheets (MSDS) or, for some items, the information in the Household Products Database maintained by the U.S. Department of Health and Human Services ( , "Inside the Home" and "Personal Care" categories).

I wash all my natural animal fibers at between 50 and 60°C (120 and 140°F), preferably on the lower end. Wool wax, the stickiest contaminant to remove, melts at 35-40°C (95-104°F) and damage to protein fibers can occur at higher temperatures. The length of time that fiber is exposed to high temperatures, and the pH of the environment, matter a great deal. Dyeing fibers involves balancing these factors in exchange for a rainbow.


A practical footnote and a random fact

Here's a quick note about washing fine wools in their raw form: When wool wax is dissolved, its chemical composition changes. If the temperature of the bath cools, the grease can be redeposited on the fiber as a scum that can be substantially more difficult to remove than it was in its original form.

Random fact
Lanolin is produced from a portion of the wool grease recovered from scouring liquid.

Deborah Robson is the author, with livestock expert Carol Ekarius, of The Fleece & Fiber Sourcebook: More than 200 Fibers from Animal to Spun Yarn. She has also worked with Interweave Press to produce the instructional DVD set Handspinning Rare Wools. She teaches internationally. Her website is at, and her blog, The Independent Stitch, is at

Simpson, W. S., and G. H. Crawshaw. Wool: Science and Technology. Woodhead Publishing Limited Series on Fibres. Boca Raton, FL, and Cambridge, England: CRC Press Woodhead, 2002.

von Bergen, Werner. Wool Handbook: A Text and Reference Book for the Entire Wool Industry. 3d enl. ed. ed. New York: Interscience Publishers, 1963.

– For more on Leicester Longwool sheep, see "On the Edge: How a Handful of People Have Preserved Some Rare, Valuable Sheep and Their Wools," PieceWork, November/December 2011

Win Your Own Unicorn Fibre Products to Clean and Maintain Your Fibers!

Unicorn Fibre, a proud sponsor of Knitting Daily TV Series 800, is helping to celebrate the show's 100th episode season with a great giveaway. Simply comment on this blog post and you're automatically entered to win a set of Fibre Wash, Fibre Rinse, and Power Scour from Unicorn Fibre. You can read more about these great products, loved and used by fiber expert Deborah Robson. Tell us what fiber you're planning to clean, what knitted sweater you're trying to maintain, or share with us a horror story of a washing malfunction that ruined your fiber or sweater. We'll randomly choose a winner from all the comments at noon Central Time on Monday, February 13th, so comment before then. Read the official giveaway rules for more details.

This blog is proudly sponsored by Unicorn Fibre. Visit their website today for more fibre care information and trusted products.

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