Natural dyeing wool with ground walnut hulls

You don’t need to be a pro in the dye room to whip up some soothing natural shades. Even beginner dyers will find that this simple to follow recipe will come together in the dye pot with ease. This Dyeing Wool with Ground Walnut Hulls Recipe was featured in our November 2020 Fiber Club Package with the decadent natural white Organic Polwarth Wool Top.

Once you unlock the secrets to dyeing your yarn or fiber with natural dyes, the possibilities and variations become endless! This rewarding and simple to follow tutorial is worthy of a dye day with friends, though it is so easy, you’ll make it a regular on your dye days. Before you get started, it’s important to read the material safety data sheets for the mordants you will be using in this tutorial.

Click here to download the Aluminum Sulfate Safety Data Sheet
Click here to download the Cream of Tartar Safety Data Sheet

As always when working with dyestuff, make sure you are in a well-ventilated area before handling any materials, wearing gloves, a mask, and using cookware that will not be used in future food prep.

Level: Easy
Total: 5 hours and 30 minutes with an overnight break
Yield: 6 oz dyed fiber with dye left over

Materials Needed: 

  • 6 oz. of an undyed wool top
  • 0.5 oz of ground walnut hulls
  • 1.5 oz of aluminum sulfate
  • 0.5 oz of cream of tartar
  • Gloves
  • Dust mask
  • Stainless steel pot – big enough to fit your fiber covered with water in
  • Thermometer
  • Zip tie – if dyeing yarn (helps to move the yarn around without agitating it too much – careful not to overtighten the zip tie or you’ll end up with a white stripe on your skein.)
  • Tongs
  • Salad spinner (optional)
  • Neutral liquid soap
  • A large bin or bowl to rinse the wool in
  • Kettle (optional)
  • Empty tea sachet (optional)



Please note, it is not necessary to mordant your fiber before dyeing with walnut. The use of alum mordant acts more like a color shifter, turning the brown produced by the walnut into a more golden, butternut, brown. Cream of tartar is the resulting sediment from fermenting grapes and is also optional to add to your mordant bath. The addition of cream of tartar will soften the wool, brighten shades, and change the color of some dyes (e.g., Fuschia of cochineal to a true red.)

If you do not wish to mordant your wool, skip to the dyeing section below. Included in our November 2020 Fiber Club Package is enough of these two mordants mixed together to mordant 6 oz. of fiber. The following are the measurements of mordant powder by tablespoon for one pound of fiber.

Aluminum Sulfate: 4 TBS
Cream of Tartar: 3 TBS

    1. Soak your yarn or fiber in warm water for 30 minutes with 1 TBS of liquid soap. We used Unicorn power scour but any neutral liquid soap will do.
    2. Rinse with warm water and remove any excess water with a salad spinner. Be careful not to agitate your wool throughout this entire process as this will increase the felting of the wool.
    3. Boil water in a kettle.
    4. With gloves and a mask on, place your mordant mixture of aluminum sulfate and cream of tartar into a stainless steel pot, careful not to breathe in the fumes.
    5. Pour boiling water into the pot over the mordant mixture and stir until fully dissolved.
    6. Add cold water to the pot, stir.
    7. Add wool to the pot and cover with water when the water temperature is at or near room temperature to reduce felting.
    8. Slowly bring your water temperature to 200°F. It is very important to raise the temperature slowly as raising too quickly will increase the chances of the wool felting.
    9. Hold this temperature for 1 hour. Be careful not to agitate the wool or it will felt.
    10. Take the pot off the heat and let cool for 1 hour or until room temperature.
    11. Rinse the fiber, without using soap, in the same temperature water as the fiber, being careful not to agitate it. This is where zip ties are handy to remove and manipulate.
    12. If you do not plan to dye the fiber right away it is important to store the wet fiber in an airtight container until you are ready to do so. Do not leave the fiber in the container for longer than 1 week. It is important to not let the fiber dry out in between mordanting and dyeing, as it can damage the fibers.



Included in our November Fiber Club Package is enough walnut powder to dye 6 oz. of fiber a light shade. The following are the measurements of dye extracts by tablespoon for one pound of fiber based on light, medium, and dark values. The measurements refer to level spoonfuls. Be aware that these are approximate measures and are only guidelines. Increase or decrease the spoonfuls based on the quantity of goods being dyed.

Light Shade: 2 TBS
Medium Shade: 4 TBS
Dark Shade: 6 TBS

    1. With gloves and a mask on, place your walnut powder into a stainless steel pot.
    2. Pour boiling water over the powder and mix until dissolved – some shell debris may be present and will not dissolve. If you wish to prevent the shell dust from contaminating your wool consider putting the walnut powder into a tea sachet first before adding your boiling water.
    3. Simmer on low flame for 2 hours. Walnut hulls contain high amounts of tannic acid as a component of juglone, the active colorant. The rich brown color develops with oxygen, so it is necessary to simmer the walnut hulls/powder in order to achieve the best color results.
    4. Take the pot off the heat and let cool down overnight or until room temperature.
    5. Add your wet fiber to the room temperature walnut dye pot.
    6. Cover the fiber with cold water and rotate very very gently, careful not to agitate the wool as this will increase felting.
    7. Slowly bring the temperature to 90°F and hold for 30 minutes gently rotating the fiber regularly.
    8. Slowly bring the temperature to 180°F and hold for 30 – 45 minutes gently rotating the fiber regularly.
    9. Take your pot off the heat and let cool down to room temperature.
    10. Use the same temperature water as your dyebath to gently rinse the fiber with soap a few times until the water is clear. Be careful not to agitate the wool as this will increase felting.
    11. Let your fiber air dry away from direct sunlight.

Dyer’s Note:

After you’ve finished dyeing, save your dye water in a jar and use it for future dye baths. The same dye water can be used several more times, producing lighter shades each time.

Fun fact: Walnut dye has been used for centuries as a base dye when dyeing with Indigo to produce even richer and darker shades of blue.