Natural Dyeing With Black Beans




Introduction: Natural Dyeing With Black Beans

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?

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.

Other posts in my Natural Dyeing Series:

Dyeing with Black Walnuts
Dyeing with Dandelions

Step 1: Supplies:

–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

Step 2: ​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.

Step 3: Soak the Black Beans

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.)

Step 4: 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.

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.

Step 5:

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

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    1 year ago

    I was soaking black beans for dinner and noticed that the water had become rather blacker than I had expected. In a burst of curiosity and inspiration, I decided that I wanted to see (without asking the internet beforehand) whether it would work as a dye. My mom, who used to own sheep and has experience dyeing wool, suggested I add lemon juice "as a mordant", so I stirred in about two teaspoons of that before I put a white scrap (cotton) and a pale pink undershirt (unknown, but likely cotton or a cotton blend) in to soak.
    The result was a lavender shade, rather than the blue you achieved, which is a very interesting disparity. That could have been due to several factors.
    1. I likely was using a different variety of black beans than you-- the beans themselves, after soaking, looked purple in the places where they were no longer dark enough to be black, so this seems likely.
    2. If basic baking soda can make the dye greener, it makes some sense that acidic lemon juice could make it purpler.
    3. The pink of the undershirt could have mixed with the bean dye. This seems unlikely-- based on the lack of fading in the years I have had it, I doubt the pink dye would have leached out into the bean dye enough to affect the color. And the fact that the white cotton scrap turned the same shade of purple as the undershirt further suggests that the original pink dye was completely overwhelmed by the bean dye.
    4. You heated your dye; I did not. Based on the way the water I cooked the beans in turned brown rather than purple or black as the soak water had, this may have a significant effect on the difference in results.
    I have not yet run the undershirt through the laundry, but based on how little dye came out when I rinsed it, way less than I was expecting based on past experiences with tie-dye, I am hopeful that the color will stay well. Of course, if my heat theory has any credence, it may come out a different shade... I hope not. I like purple.


    Reply 1 year ago

    About what was your water to lemon juice ratio? Would be interested in an update abt how the colour was affected by washing


    Reply 1 year ago

    Most of the color washed straight out. It is a less bright color than it started as, and looks pink off the bat, but based on comparison with other pinks, is actually a very subtle purple. It changed colors when I just now splashed it in different places with lemon juice (a pink slightly peachier than the original), dissolved baking soda (blueish-greyish, with pink undertones), and plain water (about the same pink as the original fabric in the middle, yellowish-brownish around the edges. An interesting effect, clearly indicating that the remaining dye still intends to wash out and was moved by the water). In one spot, the lemon juice and baking soda overlapped and turned yellowish!
    I can give you only a very vague estimate of proportions: two teaspoons lemon juice for somewhere between two and four cups of the dye water.
    I soaked the undershirt for... uh, probably less than five hours. Clearly that either wasn't enough (which makes sense, it's a lot shorter than a lot of people use for dyeing things) or the undershirt had enough synthetic fiber in it to prevent the dye from sticking. Or even, lemon juice added to the dye was not the right mordanting method.

    (Something about this sort of experimental project makes me write in a very longwinded style. Sorry if it's a bit overwhelming to read!)


    Reply 1 year ago

    Thanks for the in depth information!