Here’s the boring part — mordanting the linen and waiting for it to dry. I’m mordanting in alternating dips of soy milk and baking soda. The soy milk is because the plant dyes bond with protein molecules, and the baking soda is because they adhere better in an alkaline environment.

I’m doing several dips each of soy milk and baking soda, so it takes quite a long time just to prepare the fabric before dyeing.



  1. Hi Cassandra, thank you for sharing!!
    I am in love with ecodye. I would like to know the “recipe”.How many cups or ml of Soy milk and Tbs of baking soda per L?

    Thank you very much.

  2. Hi AM,

    I use plain soymilk — the kind that’s just filtered soy beans and water. One part soy milk to five parts water. As for the baking soda, I just throw some in without really measuring. Maybe about 1/4 cup baking soda to one liter of water.

  3. I’ve been playing around with indigo dyeing for the last year, looks great then just fades to gray. Is this because I’m only weting my fabric with water before dipping?
    after you dip in soy milk soda mixture do you rinse before dipping?
    I’m using Michel Garcias organic vat
    1 part indigo
    2 parts pickling lime
    3 parts fructose
    I got my organic indigo from botanicals colors

    1. Hi Linda,

      I’ve never used indigo, and from what I understand, it’s very different from other natural dyes. The vat needs to ferment, right? And then the color on the fabric needs to oxidize before turning blue. I’m not sure you even need mordant at all when using indigo.

      I do not rinse the soy milk/soda ash off before dyeing. I don’t think much of it would wash off even if you tried. The fabric seems to absorb most of it.

    1. Hi Heather,

      I’ve never tried adding soda ash or baking soda in with the soy milk, but I’d be interested in hearing about it if you try it. And yes, I do let the fabric dry between dips.

  4. I haven’t dyed anything yet. Just doing the how-to before spring. I especially like your work. Thanks for such information.

  5. Hi Cassandra, thanks for sharing. The last time I mordanted my fabric (silk and cotton) with soy milk, the milk curdled and the fabric got very hard. It didn’t go away even tough I washed the fabric right away. Do you have any tricks to soften the fabric or did I just waste it :(

    1. Interesting, Naz. The fabric does get a bit stiff until after I wash it, but I’ve never had it get hard before. I wonder how that happened! Have you tried boiling it out? Maybe scouring with something like soda ash if it’s cotton or another plant fiber?

  6. Hi Cassandra, Does this technique affect how well the colours stay when the fabric gets washed? I’ve been looking in to ways to reduce fading without adding nasty chemicals! Any tips would be great!

    1. Hi Abigail. I share your interest in finding ways to avoid using nasty chemicals! I believe soy milk and baking soda dips do help the colors stay put when washing, but do not help with fading from exposure to light.

  7. Hi, i’m new to natural dyeing and want to clear something , here above u have mention the recipe as soy milk and water so um confuse what we do with baking soda,
    do we have soak the material separately in in baking soda ?
    please explain the correct steps.

    1. Hi Keshala. There are so many recipes for mordanting cellulose fibers, and I prefer to use natural mordants rather than powdered metals. So what I’ve done here is to dip the linen first in diluted soy milk, let it dry, then dip it in dissolved baking soda, and let that dry.

  8. Hi Cassandra. thanks for your kindness in every answer
    I am writing to you from Argentina. Could soy milk be frozen? In what proportions do you dilute it to immerse the fabrics? I am with my first experiments … I love to contact people like you. thank you

    1. Hi Viryi. I’ve never frozen soy milk, but I don’t see why it couldn’t be frozen. Especially if you’re not concerned about the taste! When using it on fabric, I dilute it one part soy milk to five parts water. Looking forward to seeing your experiments!

Leave a Reply