Coloring with woad powder - a first attempt

[MaxB]

Woad (Isatis tinctoria) is a flowering plant that has been used for blue dye since ancient times, though it was supplanted by "true indigo" (Indigofera tinctoria) following the opening of European trade routes to India in the 1500s. Nowadays, woad powder is still less commercially available but can be found in some dye suppliers or soap supply shops (usually just a bit more expensive than indigo powder).

I've been trying out different natural colorants and recently picked up some woad powder, which I added directly to the lye solution in a recent batch (as I always do with indigo). I think my mix of oils was a little too golden (included some kokum butter and avocado oil), so the resulting soap ended up green rather than blue. I'll plan to do another batch without the kokum and avocado, perhaps some combo with pomace and shea.

This was also my first time using sweet basil EO in a soap - I foolishly bought an entire 16oz container before reading the IFRA and learning that the max concentration is 0.44%, so now I have enough to last me for 230lbs of basil-scented soap! Even at 0.4%, the basil scent quickly overwhelmed the rosemary and clove EOs with which I mixed it.

Interestingly, the cut revealed a strange swirled pattern on the interior of the soap. I'm not sure whether this is due to the woad or something else.

Has anybody else used woad in their soapmaking? Would love to hear how it worked for you!

 

[dibbles]

I have never used woad, but have seen some lovely blues created with it. The pattern you see is glycerin rivers which can happen when higher amounts of water are used and the soap goes through gel phase. I don’t often get them, but I usually don’t mind them if it happens. If you are using the default settings in a soap.calculator, you might try increasing your lye concentration to 33% to mostly avoid glycerin rivers. Your soap looks great, and in this case I think the glycerin rivers add interest.

 

[MaxB]

I have never used woad, but have seen some lovely blues created with it. The pattern you see is glycerin rivers which can happen when higher amounts of water are used and the soap goes through gel phase. I don’t often get them, but I usually don’t mind them if it happens. If you are using the default settings in a soap.calculator, you might try increasing your lye concentration to 33% to mostly avoid glycerin rivers. Your soap looks great, and in this case I think the glycerin rivers add interest.

Oh neat! First time I've seen them in one of my soaps. I usually set the calculator values for liquid as % of oils, which today I learned (thanks to one of the threads on this forum!) gives inconsistent results vs. setting the lye concentration. I was trying a new oil mix on this batch, so that could explain why I got them this time around (my lye concentration would have been ~27%). I do kind of like the look though - I bet it would work especially well with certain colors or color blends.

I am going to try another round of woad tomorrow, this time on a salt soap (95%/5% coconut/castor with 20% SF). Hopefully the lighter oil mix will give me a nice blue.

 

[Ephemerella]

I haven't used woad before, but I do use indigo quite a bit. My batter is naturally very white despite high percentage of EVOO, which is very dark green. I sometimes get lovely denim blue from indigo, but usually get the soft greenish you have in yours, which I happen to like a lot. The only variable for me is the fragrance oil. Some FOs keep the blue, most turn green. Its usually the FOs that want to accelerate a bit that turn color. I don't use EOs but from reading here Clove can be an accelerator I think... so you might want to look to a citrus or something that slows acceleration if you want to try to keep the blue of woad.

 

[Ephemerella]

Oh, a link at the bottom turned up this interesting experiment, I haven't read it though, so not sure if its helpful to you
https://www.soapmakingforum.com/threads/indigo-vat-as-soap-colourant.84739/