I have posted a reel and some info on social media about cleaning fleeces; this blog entry will have a deeper dive into the specific topic of removing vegetable matter (VM) from a fleece and the resulting fiber. (VM refers to the hay, grass, leaves etc. that works its way into a fleece.)
If a fiber animal (in the case of Withers Wool, the current fiber animals are Merino Sheep and Angora Goats) grazes and/or eats hay, VM is going to accumulate in some amount in the fleece. It is possible to reduce that accumulation by a number of means - e.g. covers on the animals (which I do not use for a variety of reasons), clean conditions, eliminating the stickier plants from the fields (such as nettles), etc. But unless the animals are in very artificial conditions (which would not be healthy for the animals), there will be some VM. One more point before I get into how to remove the VM, the characteristics of the fleece on the animal also influence the VM that accumulates. For example, generally more VM accumulates in a mohair fleece which has loose locks than a Merino fleece which is very dense. I am going to orient my discussion around 5 main stages of removing VM: (1) Skirting; (2) Washing; (3) Picking; (4) Carding; and (5) Spinning.
Skirting is the the process of removing “junk” fiber, stains, second cuts and VM from the fleece prior to washing it. The skirting process is done after the fleece is shorn and requires a skirting table with an open mesh top. (I use hardware cloth stretched between a wooden frame.) There is one other piece of equipment I use that can help, at least for mohair fleeces. My very first step is to take the mohair fleece and put it in the tumbler for about a half hour. This allows some of the second cuts and VM to fall out. (I only do this with mohair fleeces; the Merino fleeces have so much lanolin in them the tumbler twists the wool around and very little of anything falls out because of the sticky natures of the lanolin.) Then the fleece is laid on the skirting table and the large pieces of VM are removed by hand..
Washing a fleece (also called scouring) is the process of removing dirt, grease, dust, VM and other impurities from the fleece. Washing can remove smaller pieces of (non-sticky) VM. Depending on the fleece, I go through 1-3 wash cycles and two rinse cycles. A few comments about washing: avoid agitation, use hot water (the recommended temperature depends on the fleece), use an appropriate degreasing shampoo, and dry carefully - e.g. no hot air.
Picking a fleece is the process of removing unwanted material from a washed fleece. This is usually the most time consuming step in removing VM. There is no magic here; you remove the VM (and any other unwanted material) by carefully and thoroughly picking through the fleece by hand. It is hard to completely remove 100% of the VM at this point, but you can come close. At the end of this stage, there are three other things you can do to remove VM. One, use a hand comb to remove finely broken up vegetation (often called chaff). Two, if the fleece is still tightly compacted and has more small/fine amounts of VM than you desire, you can use a mechanical picker on the fleece - this both opens up the fleece as well as causes some amount of VM to fall out. Three, go one more time through the tumbler to get more of the fine VM/chaff out as well as any second cuts still remaining. (I always use the tumbler; sometimes I use a comb and/or the mechanical picker depending on the fleece.)
Next - unless you are going to spin (or otherwise use) raw fiber - is carding. Carding a fleece is a process that separates and aligns fibers to prepare them for spinning (or felting). You could use hand carders or a drum carder. I generally use a drum carder - which produces a batt. As the fleece is going thru the teeth of the carder, more VM will fall out - especially the very fine VM that may still be in the fleece.
The final step is spinning the fiber (unless you are going to use the carded fiber for felting.) If you have acquired carded fiber (e.g. roving or a batt) from a fiber studio for spinning, you have probably at some point encountered some VM in the fiber. During the spinning process, this can be removed during pre-drafting (if you do pre-draft) and/or as you spin the fiber. If it ends up in the yarn you can pick it off.
A few others notes:
- commercially mass produced fiber/yarns have had VM removed through a process called carbonization, which chemically “burns off” the VM - and alters the composition of the fiber.
- before I send any fiber to a mill (to get roving or mill spun yarn), I always go thru the first three steps: skirting, washing and picking. The skirting and picking (by hand) are particularly important; most fiber mills will wash the fleece (even if you have already washed it) but will not pick out vegetation by hand. The mill will use an automated mechanical picker and carder.
Tumbler with a mohair fleece