Wool comes primarily from sheep, harvested by shearing their fleece once or twice a year. The global wool supply totals about 2.1 million tonnes annually, with Australia producing nearly 25% of it, followed by China at 16% and New Zealand at 10%. Whether you’re looking to source wool for a project, understand how it goes from animal to fiber, or explore alternatives to sheep wool, the process is more involved than a simple haircut.
How Sheep Grow Wool
Wool is made of keratin, the same protein in human hair and fingernails. Sheep grow it from thousands of follicles embedded in their skin. Each fiber develops in layers: the inner cortex provides strength and elasticity, while an outer cuticle made of overlapping scales gives wool its distinctive texture and helps it shed water. A thin coating of a naturally occurring fatty acid on the cuticle surface makes raw wool fibers hydrophobic, meaning water beads up on them rather than soaking in. This is why sheep can stand in rain without getting waterlogged.
Most wool breeds grow their fleece continuously, which is why domesticated sheep need regular shearing. Left unshorn, the fleece becomes heavy, matted, and can trap moisture against the skin, leading to infections and overheating in warm weather.
Shearing: The First Step
Shearing is the standard method for collecting wool from sheep. A skilled shearer uses electric clippers to remove the entire fleece in one piece, working methodically from belly to back. The process takes two to five minutes per sheep and doesn’t injure the animal when done correctly. Most sheep are shorn once a year in spring, before warm weather arrives, though some breeds or climates call for twice-yearly shearing.
A single sheep typically yields between 2 and 13 kilograms of raw (greasy) wool per shearing, depending on the breed. Merino sheep, prized for their exceptionally fine fibers, tend to produce heavier fleeces than meat breeds. The fleece comes off as a single blanket-like sheet, which is then spread on a table for “skirting,” the process of removing stained, matted, or low-quality sections from the edges and belly area.
Cleaning Raw Wool
Freshly shorn wool is greasy, dirty, and full of plant matter. Raw fleece can contain 30% to 70% impurities by weight, including lanolin (the natural grease), dried sweat salts called suint, dust, and vegetable debris like seeds and burrs. All of this has to come out before the fiber is usable.
Industrial cleaning, called scouring, runs the wool through a series of water baths. The first wash bowls operate at around 25 to 30°C to dissolve the sweat salts. Then the wool moves into hotter scour bowls at 50 to 70°C, where detergents break down and remove the grease. Finally, rinse bowls at 25 to 50°C flush away remaining soap and residue. The whole process transforms a heavy, oily mass into clean, fluffy fiber ready for further processing.
If you’re working with a small amount of wool at home, the same principle applies on a smaller scale. Soak the raw fleece in warm (not hot) water with a gentle detergent, let it sit without agitating it (agitation causes felting), then drain and repeat until the water runs clear. Hot water and rough handling will turn your fleece into a matted, shrunken mess.
What Happens to the Grease
The lanolin washed out during scouring isn’t wasted. It’s collected, refined, and sold as a waxy substance used in skincare products, lip balms, and leather conditioners. Traditional extraction uses the soapy wash water from scouring, where the lanolin separates out through centrifuging. Newer methods are experimenting with high-pressure carbon dioxide as a solvent to extract lanolin without water, though this remains largely experimental.
From Clean Fiber to Usable Wool
Once scoured, the wool goes through carding, a process that untangles and aligns the fibers into a thin, even sheet or rope called roving. Industrial carding machines use drums covered in fine wire teeth that pull the fibers into alignment. For hand spinners, small drum carders or hand carders (paddle-like tools with wire bristles) do the same job.
After carding, the roving can be spun into yarn. Spinning twists the loose fibers together, creating a continuous strand with strength and elasticity. The tightness of the twist, the thickness of the yarn, and whether multiple strands are plied together all affect the final product’s texture and durability. At this point, the wool can also be dyed, either as loose fiber before spinning or as finished yarn.
Not all wool becomes yarn. Loose carded fiber is used for felting, insulation, mattress padding, and stuffing. Wool’s natural fire resistance and moisture-absorbing properties make it useful well beyond clothing.
Wool From Other Animals
Sheep aren’t the only source. Several other animals produce fibers that fall under the broad category of “wool,” each with a different harvesting method and character.
- Alpaca: Sheared once a year using electric clippers, similar to sheep. Alpacas are native to the high-altitude Andes and produce a fiber that’s lighter and warmer than sheep wool, with a silky sheen. It’s also naturally hypoallergenic, making it a good option for people who find sheep wool itchy.
- Cashmere goat: Unlike sheep, cashmere goats aren’t sheared. Their fine undercoat is combed out by hand during the spring molting season, a slow process that yields only a few ounces of usable fiber per goat per year. The raw fiber then has to be separated from coarser outer guard hairs, which is why cashmere costs significantly more than sheep wool.
- Angora rabbit: Produces an extremely soft, fine fiber that’s either plucked during natural shedding or clipped. Angora fiber is very warm but too delicate to use on its own, so it’s typically blended with sheep wool or other fibers.
- Yak: Like cashmere goats, yaks produce a soft undercoat that’s combed out during spring shedding. The fiber is warm, soft, and increasingly popular as a luxury alternative.
Where to Source Wool
Your options depend on what form you need and how much processing you want to do yourself. Raw fleece can be purchased directly from sheep farms, at fiber festivals, or through online marketplaces. Buying raw gives you the most control over quality but requires you to wash, card, and spin it yourself. Expect to pay anywhere from a few dollars to $30 or more per pound depending on the breed and quality.
If you want to skip the messy stages, roving (cleaned and carded fiber ready for spinning or felting) is widely available from fiber shops and online retailers. For knitters and weavers who don’t spin, finished yarn is the most accessible option, sold by weight at craft stores, yarn shops, and directly from small-scale producers.
For bulk or commercial needs, wool is traded as a global commodity. Australia, New Zealand, and China dominate production. Wool is graded primarily by fiber diameter, measured in microns. Merino wool, the finest and softest, runs 11.5 to 24 microns. Coarser breeds used for carpets and outerwear can exceed 40 microns.
Ethical Sourcing
Animal welfare in wool production has drawn increasing attention. The Responsible Wool Standard (RWS), managed by Textile Exchange, certifies farms that meet requirements based on the Five Freedoms of animal welfare: freedom from hunger and thirst, discomfort, pain, fear, and the ability to express normal behavior. RWS also evaluates land management and social practices on farms. If welfare matters to you, look for the RWS label or buy directly from farms where you can ask about their practices.
The most common welfare concern in conventional wool production is mulesing, a surgical procedure used primarily in Australia to prevent flystrike in Merino sheep. Many brands and certifications now require mulesing-free wool, and breeding programs are producing sheep that don’t need the procedure. Asking your supplier about mulesing status is straightforward, and most small farms outside Australia don’t practice it at all.