What happens when cashmere gets wet?

Getting cashmere wet is not inherently bad—in fact, water is essential for the “blooming” process that gives cashmere its signature softness. However, the fiber is in its most vulnerable state when wet.¹

Here is the technical breakdown of what happens to the fiber, which is useful for explaining care instructions to your customers.

1. The “Wet Dog” Smell (Chemical Reaction)

The most immediate thing you notice is a distinct, musky animal odor (often described as “wet dog”).

• Why it happens: Cashmere is a natural animal hair (protein fiber).² When water penetrates the hair shaft, it releases natural organic compounds and gases trapped within the fiber.

• The Verdict: This is normal and actually a sign of authenticity. Synthetic (acrylic) cashmere will not smell like this. The smell evaporates completely once the fiber is dry.

2. Loss of Tensile Strength

Unlike cotton (which gets stronger when wet), cashmere loses about 30% of its tensile strength when wet.

• The Risk: The weight of the water pulls on the weakened fibers. If you lift a wet cashmere sweater by the shoulders, the weight of the water will drag the fabric down, causing irreversible stretching or even tearing at the seams.

• Handling: This is why wet cashmere must be supported from underneath (bunched up in a ball) when moving it, never dragged or hung.

3. The “Bloom” (The Positive Effect)

In manufacturing, the first wash is crucial.

• Relaxation: Water relaxes the tension in the yarn created during the spinning and knitting process.

• Bursting: As the fibers swell with water and then dry, the yarn “bursts” or “blooms.” This releases the microscopic ends of the fibers, creating the halo (the fuzzy layer) that makes cashmere feel soft. A brand-new, unwashed cashmere sweater often feels harder and tighter than one that has been washed.

4. The Felting Danger (Scales Opening)

Cashmere fibers have microscopic scales (like fish scales) along their surface.

• When Dry: These scales lie flat.

• When Wet: The scales swell and open up slightly.

• The Danger: If you add agitation (rubbing/twisting) or heat while the scales are open, they will interlock like Velcro. Once they lock, they cannot be unlocked. This is felting (shrinking). This is why you never wring out cashmere or put it in a tumble dryer.

Summary

Water resets the “memory” of the fiber.

• If you lay it flat to dry: The hydrogen bonds reform in the correct position, removing wrinkles and restoring the shape.

• If you hang it to dry: The bonds reform in a stretched position, ruining the fit.