Vegetable Matter

Ah, the age-old question about vegetable matter in fleece -- be it alpaca, wool, or something else.

I was once asked, "Why don't you remove all the vegetable matter from your fleeces?" The venue was a fiber show and as the discussion continued, it became clear that the question wasn't just about some hay in one of my fleeces, but the amount of vegetable matter in most of the fleeces at the show. The individual asking the question was almost distressed about the level of contaminants in natural fiber.

I probably didn't handle the question well. It's a hard question to handle well. The truth is that alpacas -- at least our alpacas -- live in the real world that includes hay, grass, burrs, manure, and all the usual accoutrements of pasture life. We keep our alpacas on pasture with three-sided sheds for shelter. They graze in the rain if they feel like it. While we are making efforts to remove them, we have burrs in our pasture. Our alpacas roll in the burrs if they feel like it.

Reality is that natural fiber grown in normal agricultural conditions will have vegetable matter contaminants.

I am aware of one and possibly two methods for removing all vegetable matter from animal protein fibers such as wool and alpaca. One involves harsh chemical treatments and is probably not available in the United States. I've heard hints, but can find no concrete information about the second. Beyond these two methods, there are a variety of small commercial machines purported to reduce the amount of vegetable matter in a fleece

Cooking the fleece in Sulfuric Acid
There is a method of removing vegetable matter from wool that involves heating the wool in sulfuric acid under controlled temperature conditions. Under the right conditions, sulfuric acid reacts more quickly with cellulose than it does with protein. Since cellulose is the main component of most plant materials, vegetable matter can be chemically reduced to ash without too much damage to most of the wool. Essentially, the vegetable matter is converted to guncotton and then burned to ash while the slower-reacting and fire-resistant wool remains.

Chemists in the audience might, however, speculate about what happens to keratin when cysteine is exposed to sulfuric acid and heat.

Hand-processing advocates will tell you -- and I don't know if it is true -- that more people are allergic to chemicals created or left behind by harsh chemical processing of wool than are actually allergic to wool.

Wool processed using this method generally feels harsher and more brittle to me than wool cleaned by other means. I don't really want to apply this process to my alpaca fiber.

At any rate, I don't have the facilities in my kitchen to cook alpaca fiber in hot sulfuric acid. My understanding is that there are no longer any commercial facilities anywhere in the United States capable of processing fiber using this method. I don't particularly want to subject my alpaca fiber to this method, but I would have to send my alpaca fiber out of the country for processing if I wanted to.

Crushing vegetable matter to dust
I have heard references to a process where wool is dried until vegetable matter becomes brittle and then crushed so that the vegetable matter is crushed to dust. Unfortunately, I can find nothing more than hints that the process exists. I cannot find any description of how the process works, nor can I find any reference to a mill or processor actually using the technology.

Crushing makes sense for reducing burrs and seeds to dust. I think it might help break up straw to the point it falls out more easily during carding. I don't see crushing helping much to remove high-quality hay unless the process is aggressive enough that it starts to damage the fiber. Still, I'd love to try the crushing process on some of my fleeces to see what happens.

If anyone has any information about a facility that can apply this technology, I'd love to hear about it.

Other Methods
Small commercial machines to shake vegetable matter and other contaminants out of fiber do exist. They don't remove all vegetable matter, just some of it. Commercial drum carders remove some vegetable matter -- depending on the nature of the fleece and the contaminant -- from the fleece, but again they don't remove everything.

In my processing, I skirt my fleeces to the limit of my patience. I comb and clip a lot of tips. Sometimes I put the fleece aside and come back to it when I have more patience. In my early days of hand-processing fiber, I got a number of thistle stickers in my fingers -- drawing blood -- while spinning a fleece I had prepared. Worse, I was sitting in a spinning circle trying to sell fiber when it happened. The memory of those slivers motivates me when I skirt my fleeces.

I keep tweezers handy when I'm carding and I remove a lot of vegetable matter from the fleece during carding. Even more falls out on it's own as evidenced by the pile of vegetable matter and sand that accumulates under the drum carder.

I stop and pick vegetable matter from the yarn while I'm spinning. Other debris falls from the yarn during the drafting process. Dust and small pieces of vegetable matter collects on my lap during spinning. Ideally, fleeces are clean enough that I don't stop often while spinning, but no roving is perfect.

I read blogs where knitters are commenting (complaining?) about vegetable matter in fancy, high-end knitting yarns. I talk with small commercial processors who have vegetable matter in their product. I'm not the only one who has problems with vegetable matter.

I've come to the conclusion that I can't remove all vegetable matter. I have to live with some vegetable matter in the fiber I process. I try to remove as much as I can as early in the process as possible. At some point, however, removing the additional vegetable matter is not worth the effort -- and in some cases doing so creates more problems than it solves.

Next time you encounter vegetable matter as you're spinning or knitting, just remember, a little vegetable matter is the price of a soft yarn. And, if you encounter excessive vegetable matter in something I sold, please do let me know.