Wool Care 101: Color, Cold Water & a Little Dye Science

Caring for Non-Superwash Wool

Because we’re primarily a non-superwash fiber dyer, we think it’s important to talk not only about what makes these fibers so special, but also about how to care for them once they leave our dye pots. One of the questions—and occasional moments of panic—we see most often is around color loss and pigmented wash water, so we wanted to share a little of the science behind what’s happening and why proper washing matters.

Non-superwash wool is pretty magical stuff. It’s warm, breathable, resilient, and retains the natural structure of the wool fiber—but that also means it likes to be treated a little differently in the wash.

Our golden rule? Cold water, wool-specific soap, minimal agitation, and no long soaks.

Why do we recommend COLD water?

And when we say cold, we really mean cold—not tepid or lukewarm.

Wool is a protein fiber with a naturally scaly surface. As water temperature increases, the fiber can swell and dye molecules become more mobile. That means warmer water can increase the potential for color to migrate out of one area and into another. Heat combined with agitation also increases the risk of felting in non-superwash wool.

Cold water helps minimize both of those risks, protecting the color and the structure of your finished fabric.

Help! My wash water has color in it.

First: pigmented wash water does not necessarily mean your yarn was improperly dyed.

Even properly dyed and thoroughly rinsed yarn can release some residual dye during washing, particularly with deeply saturated colors. Certain dye colors can also be more challenging than others to fully rinse of any residual, unbound dye. And it takes surprisingly little dye to turn an entire basin of water a very dramatic color.

It’s also worth remembering that color loss isn't unique to hand-dyed yarn. Many of the clothes and textiles we buy release color when they're new—we just usually don't notice because they're tumbling around inside a washing machine where we can't see the wash water.

Ever bought a brand-new pair of dark blue jeans and accidentally tossed a white T-shirt into the wash with them? You probably learned pretty quickly why we're told to wash dark colors separately. The same basic idea applies here: deeply saturated textiles can release color, and the conditions they're washed in can affect whether that color simply goes down the drain or ends up somewhere you didn't want it.

Seeing color in the water and seeing that color transfer onto another part of your project are two different things.

So what causes color transfer?

There isn't a single cause. Color transfer can result from excess or poorly fixed dye, but it can also happen when a properly dyed yarn is washed under conditions that encourage dye migration.

Temperature is a big one. Washing a deeply saturated garment in hot or warm water can increase dye mobility and encourage color loss that may not have occurred in a cold wash. If that saturated color is sitting next to cream, white, or another pale shade, some of the released dye may have an opportunity to migrate into the lighter fiber.

Long soaking times, agitation, inappropriate detergents, and changes in the chemistry of the wash water can also contribute.

That’s why how you wash your handmade woolens matters just as much as what you wash them with.

What about vinegar? Doesn't that “set” the dye?

Please don't add vinegar, citric acid, or another acid to the wash water in an attempt to set the color in a finished project.

Acid is part of the chemistry used to dye wool with acid dyes. Once loose dye is already circulating in the water, changing the pH can alter how that dye interacts with the wool. With a high-contrast project, the last thing we want to do is create conditions that could encourage mobile dye to attach to a lighter section.

Setting dye is part of the dyeing process, not something your finished sweater should need you to do at home.

Our recommended wash routine

Hand wash your woolens in cold water with a small amount of wool-specific soap. Gently submerge the piece without scrubbing or excessive agitation, and avoid prolonged soaking—particularly with high-contrast colorwork.

Rinse with cold water as needed. Gently remove excess water without wringing, then roll your project in a towel and press to remove additional moisture. Reshape and lay flat to dry.

For high-contrast projects—especially a deeply saturated shade paired with cream, white, or another pale color—we recommend being particularly mindful during the first few washes. Keep it cold, keep it gentle, and don't let it hang out unnecessarily in the wash water.

The big takeaway

Color in the wash water isn't automatically evidence of a dyeing problem, and color transfer doesn't automatically tell us why it happened.

Dye chemistry, fiber, water temperature, pH, agitation, soaking time, and color saturation can all play a role. Some colors and dye formulations may release more visible residual color than others, which is another reason the appearance of the wash water alone doesn't tell the whole story.

Non-superwash wool isn't difficult to care for—it just appreciates a little respect. Wash it cold, use a wool-specific soap, handle it gently, and lay it flat to dry.