If there’s one thing I have learned about making soap, it’s that things don’t always turn out according to plan. Lately we’ve been experimenting with using natural colorants for our soaps, and I am doing the R&D work, with a little help from my wife. I have been infusing olive oil with natural ingredients like annatto seed (orange), madder root (pink/red) and alkanet root (pinkish red to purple). After infusing, we use the oil to replace some or all of the olive oil in our soap recipe. This soap uses the alkanet infused olive oil for color.
Alkanet powder is made from the roots of the Alkanna tinctoria plant, and has been used as a dye since ancient times. To infuse the oil, I mixed two tablespoons of alkanet root powder into one cup of olive oil. I did this in a pint size glass jar, which I then put in a crock pot half-filled with water. I turned the slow cooker on low and let the jars sit for about eight hours. Then I strained the oil through a paper coffee filter. The oil wound up the color of blackberry juice, or a merlot wine.
After gleaning what information I could from my favorite online soap making resources, I decided we would use the alkanet infused oil to replace 15% of the total oil weight of the recipe. Since our recipe called for 450 grams of oils, that meant about 67 grams of the alkanet infused olive oil. So far, so good, right?
We used a base recipe we had used before, so the only real unknown in the soap was using the alkanet for coloring. I was aiming for a light to moderate shade of purple, not that it really mattered. That same day we also made a soap colored with madder root. Both were poured into our PVC molds that we lined with freezer paper. In the above photo you can see how the two soaps looked right after pouring.
After two days, we got the soaps out of the mold and cut them into slices. At this point, the alkanet soap was what I would call a medium shade of purple, as you can see in the above photo. We let the slices dry and cure for about four weeks before using. I was anxious to try them out, and waiting was not easy. During the curing, the alkanet soap kept getting darker and darker until finally it was almost black. So much for a light to medium colored soap!
I was initially concerned that the color would bleed out and stain the washcloth, or make purple lather. I am happy to report that neither happened. The soap lathers up nicely, with fluffy and creamy white lather. So even though this soap didn’t turn out exactly as we planned, it is still a great smelling and looking soap. For the next batch I think we will cut the amount of alkanet infused oil to perhaps 5% of the total oil weight, or about 22.5 grams. In the meantime we have other soap projects in the works involving naturals colors, so stay tuned.
This soap features a blend of olive, coconut, palm, and castor oil, with cocoa butter and avocado oil added for their skin nourishing qualities. Goat’s milk is used for its moisturizing and emollient properties as well as for the smooth and creamy lather. The primary scent comes from lavender essential oil, with base notes from patchouli. Tea tree essential oil is added for its beneficial properties.
Please refer to the cold process instructions here if you are new to making soap. Always take the proper safety precautions (we wear rubber gloves and goggles when mixing and making the soap).
For more recipes and soap information, check out my wife’s Soap Recipe page. I’ll be back soon with more adventures. Until then, Happy Growing (and soaping) from Happy Acres!
Purple is my favorite color and I love the look of your lavender goat’s milk soap. I am going to share this with my facebook page. I’ve been trying to drive some traffic your way, but I don’t think my timing has been right. I will keep trying.
You nailed the color! I’ve been playing with Alkanet root for lavender soap too, and it can be quite temperamental. Sometimes it’s too light, sometimes too dark, sometimes not really purple. It doesn’t help that pH has a significant effect on the final color too. I did have one batch that was much darker than I was aiming for, almost black in fact, and bled color profusely. That’s now sitting in a box waiting to be donated, and rebatched, at Clean The World. I love your soap though, the cured color is simply perfect! Great job!
Thanks Clare! It was really tough getting the photos to do the color justice. It is fun working with the natural colors, despite the uncertainties.
Great blog post and write-up. I love the comparison and seeing the results. Alkanet is my absolute favorite natural colorant for soap.
Thank you for this great post! I was wondering if you have tried using lower amounts of alkanet infusion and if you were successful in achieving a lighter shade of purple? I know it has been a while since you wrote this and I hope you can share your progress with a newbie!
So far I have not done more experimenting with the alkanet. I have worked with other botanicals, but not alkanet.
I have tried your suggestion for mixing the alkanet powder, as well as some others but cannot get purple. This is also true for other colors. I have a goat dairy and all of my soups are goat milk soaps and no matter how slowly I add the lye to the milk it always turns yellow. The result being that any color I add does not make the desired color, for example if I want red and add red color I get orange (red and yellow). Purple (Alkanet) and yellow makes brown.
Any suggestions would be much appreciated!
It’s been awhile since we made goat’s milk soaps, but as I recall we froze the milk to keep the liquids cooler when adding lye. We also kept the containers in an ice bath to help keep it cool. That’s about all I can think of, hope it helps.