Spinning silk into usable yarn involves two fundamentally different processes depending on your starting point. If you’re working from raw cocoons, you’ll first need to reel or extract the fibers before any spinning happens. If you’re starting with commercially prepared silk fiber, you can spin it directly on a spindle or wheel, though silk’s slippery nature demands different techniques than wool. Here’s how the full process works, from cocoon to finished yarn.
Reeling vs. Spinning: Two Paths to Silk Yarn
A single silkworm cocoon contains a continuous filament that can stretch over a kilometer long. In traditional silk production, that filament is reeled, not spun. Reeling means unwinding the intact thread from the cocoon and combining several filaments together to form a strong, glossy yarn. This is how most commercial silk fabric gets made.
Spinning, by contrast, is what happens when those long filaments get broken into shorter pieces. This occurs naturally when a moth chews its way out of the cocoon (as in Ahimsa or “peace silk” production), or when leftover waste silk from reeling is processed into shorter fibers. These short fibers must be twisted together, just like cotton or wool, to form a continuous yarn. The result has a more matte, textured finish compared to the high gloss of reeled silk. Both paths produce real silk yarn, but with distinctly different characteristics.
How Silk Is Reeled From Cocoons
Reeling starts with softening the cocoons in hot water, a step called cocoon cooking. The cocoons are placed in water held at 95 to 97°C for 10 to 15 minutes. This dissolves enough of the natural glue (called sericin) holding the cocoon together that the filament can be pulled free without breaking.
Next comes deflossing: removing the loose, tangled outer layer of silk that can’t be reeled cleanly. Once that’s stripped away, the cocoons are brushed by hand or with a mechanical brush to find the true end of the continuous filament underneath. This is the critical moment. Finding the right thread end is what makes the difference between a clean reel and a tangled mess.
The filament ends from several cocoons are then gathered together, passed through a guide that twists them lightly around each other, and wound onto a reel. A single cocoon’s thread is too fine to be useful alone, so combining multiple filaments creates a yarn with usable strength. When one cocoon runs out of silk, another is immediately added to keep the yarn continuous and uniform. This substitution requires constant attention from the operator, making reeling a skilled and labor-intensive craft.
Removing the Natural Glue
Raw silk straight off the reel still has sericin coating the fibers, which makes it stiff and dull. Removing this glue, called degumming, reveals the soft, luminous fiber underneath. The traditional method uses soap in an alkaline bath (around pH 10) heated to 92 to 98°C for anywhere from 45 minutes to several hours. Historically, Marseille soap was the standard choice.
Acids like citric or tartaric acid can also strip sericin, typically at a full boil for about 60 minutes. For those looking for gentler alternatives, enzyme-based degumming works at much lower temperatures (around 50°C) and neutral pH, achieving comparable results in about 30 minutes. The method you choose affects the fiber’s final texture and strength, with enzymatic methods generally preserving more of silk’s natural elasticity.
Preparing Silk Fiber for Hand Spinning
If you’re a hand spinner, you’ll most likely be working with commercially prepared silk rather than raw cocoons. Silk comes in several preparations, and how you handle each one matters.
Silk bricks (also called silk batts) are dense, compressed blocks of long, aligned fibers. The biggest beginner mistake is trying to feed the brick directly onto a wheel or spindle. Instead, pull the brick apart into thin strips first, then pre-draft those strips to loosen the fibers before you begin. Without this step, you’ll end up with a snarled mess wrapped around your wheel’s orifice.
Silk tops are combed preparations where the fibers run parallel, similar to wool top. Silk caps are made by stretching degummed cocoons over a form, creating thin, layered sheets you peel apart and draft from. Both can be spun smoothly, but all silk preparations benefit from one particular technique: spinning from the fold. Pull off a small section of fiber, drape it over your index finger, and use the folded point as the tip of your drafting triangle. This gives you much better control over silk’s notoriously slippery fibers.
Spinning Technique for Silk
Silk behaves more like cotton than wool. The fibers are smooth, fine, and have almost no grip on each other, so the techniques that work for wool (short draw with lots of pinching) will fight you here. Experienced silk spinner Sara Lamb recommends a long-draw approach: draft the fiber supply back with one hand while controlling twist with the other hand forward. Keep both hands open and relaxed rather than pinching the twist off. Pinching creates tension that leads to hand fatigue and uneven yarn over long spinning sessions.
Your hands themselves matter more than you might expect. Dry or rough skin catches on fine silk fibers and makes drafting miserable. Keep your hands well moisturized before and during spinning. Some spinners apply a light lotion before sitting down at the wheel.
For drop spindle spinning, choose a lightweight spindle, ideally around 28 grams (about one ounce), that spins long and fast. Heavier spindles will snap the fine fibers. Silk takes twist readily, and you generally want a moderate to high twist to compensate for the fibers’ lack of natural grip on each other.
Managing Static and Flyaway Fibers
Silk generates static electricity easily, especially in dry environments. Those tiny fibers floating away from your drafting zone aren’t just annoying; they make it nearly impossible to spin a consistent yarn. The simplest fix is humidity. Spin in a room with a humidifier running, or at minimum keep a damp towel nearby. Some spinners lightly mist their fiber with water from a spray bottle, though too much moisture can make the fibers clump.
If you’re spinning frequently, a small amount of spinning oil or fiber conditioner applied to the silk before drafting can reduce static. Go sparingly. You can always wash the finished yarn, but too much oil during spinning makes the fibers slide apart even more than they naturally want to.
Setting the Twist
After spinning, silk yarn holds internal tension from the twist. If you skip the setting step, your yarn will kink and curl back on itself when you try to knit or weave with it. For hand spinners, the simplest method is to wind the yarn into a skein, soak it in warm water, and hang it with a light weight to dry. The moisture and gentle tension allow the fibers to relax into their twisted position.
In commercial production, wound bobbins are loaded into a steam chamber where controlled steam penetrates the yarn structure, distributing the twist evenly and locking it in place. Home spinners can approximate this with a garment steamer held over a hanging skein, though a plain warm-water soak works perfectly well for most projects.
Ahimsa Silk: A Different Fiber Entirely
Conventional silk production kills the silkworm inside the cocoon before reeling. Ahimsa (or peace) silk lets the moth emerge naturally, but the moth breaks the continuous filament on its way out. What’s left are short, irregular fibers that can’t be reeled at all.
These shorter fibers must be carded or combed and then spun like any other staple fiber. The resulting yarn has a visibly handcrafted quality: matte rather than glossy, slightly irregular, with a softer drape than reeled silk. If you’re drawn to silk but uncomfortable with conventional harvesting, Ahimsa silk fiber is widely available from fiber arts suppliers and spins up beautifully with the same techniques described above. Just expect a yarn with more texture and less sheen than its reeled counterpart.
Protecting Your Lungs
One often-overlooked concern for regular silk spinners is fiber dust. Fine silk particles released during carding, drafting, and spinning can irritate the respiratory system over time. Research from the CDC has identified silk dust as a contributor to chronic lung disease in textile workers with long-term exposure. If you spin silk regularly, work in a well-ventilated space and consider wearing a dust mask during fiber preparation, when the most particles become airborne.