Natural Yarn Dyeing with Black Beans

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How to Dye Yarn or Fabric with Black Beans – a Natural Dyeing Tutorial

Here comes another experiment in my Natural Dyeing Series. Did you know that you can dye fabric and yarn with food? Before the invention of synthetic dyes, people dyed all of their fabrics and yarn with natural things like tea, onion skins, red cabbage and other plant materials. So, let’s try natural dyeing with black beans.

This time, I dyed some cotton yarn and an alpaca/merino blended yarn with good ole black beans. Did I get black yarn? Nope. Blue and green. Weird, huh?

Other posts in my Natural Dyeing Series:
Dyeing with Black Walnuts
Dyeing with Dandelions

Natural Dyeing with Black Beans, a Tutorial

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I was curious to see how the different materials would take the color from the black beans. In my research, I found that cotton is more difficult to dye with natural materials than protein (animal) fibers. This turned out to be true as the cotton yarn came out a much lighter blue than the alpaca/merino blended yarn.

Natural Yarn Dyeing with Black Beans

Black Bean Dyeing Supplies:

Natural Dyeing with Black Beans, a Tutorial

Light colored Yarn (not synthetic)
Alum (Mordant)
Dry Black Beans (16 oz)
-Large pot for soaking the beans
-Large pot for mordanting the yarn (no longer safe for food prep)
-Jars or Bowls

Mordant the Yarn:

Safety Note: Alum is a fairly harmless mordant, however, caution should be used when handling more toxic mordants. Always wear gloves and a face mask.

There seem to be a lot of differing opinions on the correct amount of mordant to weight of yarn so I kind of averaged it out to about 8-10% alum.

Dissolve your alum in a disposable container with hot water. Fill the dye pot about half way with warm water and add the pre-dissolved alum. Add the yarn or fabric and bring the water to a light boil. (At this point, you want to stop stirring. Wool fiber will felt with agitation.) Simmer about 45 minutes. Turn off the heat and allow the yarn to cool to room temp. Now, you can either let it dry for later use or immediately move to the dyeing phase.

Soak the Black Beans:

Natural Dyeing with Black Beans, a Tutorial

Put your dry beans in a pot or bowl, then add just enough water to cover them. Give em a stir and let them soak. As the beans absorb the water, occasionally add more to just above the top of the beans. Keep stirring once in a while and adding water as needed. Let them sit at least one full day or longer. Don’t stir the beans for about an hour before you’re ready to use them.

Carefully, strain the liquid from the beans. Make sure there are no bean particles left in the liquid as they will leave discolored spots on the yarn. (Don’t throw out the beans! Now you can cook them.)

Dye the Yarn:

To dye the yarn, simply put the black bean liquid in a jar or bowl, then add your yarn. Let this sit for a day or two and you get blue yarn! Adding baking soda to the liquid changes the PH factor (acidity) and that gives a green dye.

Natural Dyeing with Black Beans, a Tutorial

1. Undyed, white cotton yarn
2. White, cotton yarn dyed with black beans
3. Alpaca/Merino yarn dyed with black beans
4. Alpaca/Merino yarn dyed with black beans and added baking soda
5. Undyed, Alpaca/Merino yarn

Gently wash your yarn by soaking in warm water with some mild detergent. Rinse in the same temperature water as the soak bath to prevent felting. Hang to dry and then your dyed yarn is ready to knit or crochet.

I have not time tested this yarn to see about fading but from my research it seems that the black bean dyed yarn will fade somewhat when exposed to sunlight.

Have you tried natural dyeing? What methods worked for you? I’m ready to learn more!

Dyeing with Black Walnuts
Dyeing with Dandelions

Natural Dyeing with Black Beans

Natural Dyeing Yarn with Black Beans, a tutorial


  1. I did a natural dyeing experiment in high school. Now I wish I’d kept the yarn!

  2. Kalli Walsh says

    Hello! I definitely look forward to trying this tutorial!

    SInce you mentioned that the colors will fade in sunlight, isn’t there something you can add to prevent this? I remember during a summer camp, we made tye dye shirts, an added something to the shirts before we added the dye to prevent it from fading. I still have the shirts and they are as rich as ever! ( Even after fourish Years! ) I unfortunately don’t remember what it was called, but I’m sure with research it can be found again.

    I don’t know if it will work on yarn, but it will work on cotton fabric.

    • Hi Kalli!
      That was probably soda ash which is used with a lot of fabric dyes. It can be added as a mordant for cotton which would help. Unfortunately tho, most natural dyes will fade eventually. There are a few exceptions, like black walnut but the majority are not colorfast.

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