How To Dye Cotton Blue With Black Beans (DIY Iron Mordant)

In this tutorial I’ll show you how to dye cotton fabric blue with black beans using DIY iron mordant and the cold dyeing process.

You’ll Need:

black beans
pre-washed cotton fabric, cotton yarn or cotton clothing
DIY iron liquor mordant

Soak 1 cup of black beans in enough water (more water won’t weaken the dye solution, but the fabric will dye more evenly). Be careful: the black beans will also stain your soaking pot, such as a porcelain bowl. Don’t ask me, how I know! 😉

Let the beans soak for about 24 hours.

Mordant your yarn or fabric with DIY iron liquor.

Remove the beans from the dye solution (and use them for cooking). The dye solution is now dark blue. Soak the fabric or yarn in the dye solution as long as you like. Then rinse in water.

red cabbage dye sample — Red cabbage and black beans dye samples

I used cotton yarn and let it soak about 12 hours. The yarn dyed with black beans is darker than the yarn dyed with red cabbage.

Here are more dye experiments with black beans.

6 thoughts on “How To Dye Cotton Blue With Black Beans (DIY Iron Mordant)”

Hi Lina, I’m from Spain- Canary Islands. So happy to read your blog, and I love this types of post !! I’m starting to learn about how to make a natural dye because I’m doing a grade of this on skillshare (maybe you are interested too) and I study Fashion Desing.

In these days I will try to dye whit avocado and onion skins and black beans 🙂

Lina says:

16th September 2016 at 4:33 pm

I’m glad you liked the post. 🙂 Have you already tried the natural dyes? And thanks for pointing me to skillshare – it sounds interesting.

Reply

Hi,

Just happened to see your site about natural during, do you rinse the fabric after dipping it in the iron liquor solution & how long do you soak the fabric in the iron suction ? They say too much of iron can be harsh for the fabric.

Thank you

Lina says:

2nd July 2019 at 9:19 pm

Hi Neeti, I dip the fabric into the iron liquor (for less than a minute), dye the fabric with black beans and then rinse the fabric with water.

And yes, too much iron weakens or even destroys the fibers: I once made a dye experiment and let the fabric soak in iron liquor for weeks. The iron liquor dyed the fabric a beautiful orange but the iron was very harsh on the fabric.

Reply