Testing New Herbs, Spices, & Clays in Cold Process Soap

IMG_0266-KMI decided to try out some new herbs, spices, and clays. It seems that with every swirl I want to try or every soap challenge I enter, I’m stuck using the same natural colors I’ve always used – indigo, charcoal, paprika, cocoa, walnut hull, and a variety of clays. But after so many orange and blue or black and white soaps, I’m beginning to get a bit bored. Lots of people already have great blogs and information on most of these, but it’s always a good idea to test and figure out how they work in your own soap. I ended up with some great new ideas and one soap with a cool looking alien spider swirl. :)

In the post below, I mention usage rates and infused oils. The usage rates are just what I tried for this test. They are not right for every soap recipe or every soap maker. I try to always add just enough and not overdo it (so the lather in my soaps is always white). You should test your own soap additives and never add more than what’s recommended as safe for the skin.

You’ll notice that my infused oils in this post are mostly done with olive oil. It’s simply what I had at the time. I use a grade A olive oil from Soaper’s Choice that doesn’t affect the color of the herb or spice. But normally when infusing oils, I prefer high oleic sunflower oil due to it’s very light color.

Because a recipe can definitely affect the color of the soap, I wanted to include this, as well. I used my slow-tracing swirl recipe (5% Superfat). This recipe can take longer to remove from the mold (depending on the environment and your water usage) and longer to cure; not to mention the infused oils that are added to each cup of soap. I do use a water discount, but most of my heavily natural colored swirl soaps need 6 weeks minimum to cure. But they still make great soap when they’re finally ready.

  • Olive Oil – 45%
  • Coconut Oil – 25%
  • Organic Palm Oil – 15%
  • Sunflower Oil (high oleic) – 9%
  • Avocado Oil – 3%
  • Castor Oil – 3%

Using herbs, spices, and clays can add wonderful properties to your cold process soap, while also giving the soap a unique color. Some of the herbs, spices, and clays in my test have been sitting in a box in my soap room for months, while others were just ordered in the past few weeks. The only thing I was unable to find was woad powder. It is and has been out of stock everywhere (for a reasonable price, that is). But since I’m so happy with indigo, I figured I could wait on the woad.  Here’s the list of herbs, spices, and clays you’ll see in my soap tests:

Alkanet Root Powder
Annatto Seed
Activated Charcoal
Indigo Root
Kaolin Clay (white)
Madder Root
Moroccan Red Clay
Nettle Leaf Powder
Paprika Powder
Red Sandalwood Powder
Safflower Powder
Spirulina Powder

Each herb, spice, or clay was either dispersed in water/oil, infused in oil, or added straight to the soap at trace. I’ll describe that below and how much of each I used.

When I started to prepare the recipe for these tests, I intended to just make a single soap with each herb, spice, or clay. But because I wanted the soap to gel and can never get my single guest soap tray to ever gel consistently (especially in Winter), I decided to just do 3 separate batches with swirls of colors in each batch. Granted, not knowing exactly how the colors would end up in the final soap was a gamble. And I did end up with one super ugly batch.

Batch #1 – Indigo, Nettle Leaf, Madder Root, and Safflower

This was, hands down, the ugliest soap of the three. I think I really expected the Madder root to be more of a pink color (I’ll use less next time). And even though I made an infusion with the Madder root, I obviously didn’t strain it enough (speckled). I also ended up blending the Safflower soap WAY too long which wreaked havoc with my circling Taiwan swirl. But I did find a beautiful lime green (Nettle Leaf) and pale yellow (Safflower) that I will continue to use (the soap below is a better example of these two colors).

Here are the details and usage rates for this batch:

  • Indigo Root Powder (infused in olive oil) – 1 teaspoon per cup of soap
  • Nettle Leaf Powder (infused in olive oil) – 1 tablespoon per cup of soap
  • Madder Root Powder (infused in olive oil) – 2 teaspoons per cup of soap
  • Safflower Powder (dispersed in water) – 1 tsp per cup of soap

As I mentioned, my circling Taiwan swirl really didn’t swirl very well due to me over-blending the yellow. But I did end up with a cool alien spider swirl. You can also see the yellow and green a bit better here.


Batch #2 – Indigo & Activated Charcoal, Kaolin Clay (white), Moroccan Red Clay, and Red Sandalwood Powder

Of the three batches, this was my favorite because I discovered a red that I really like. And it wasn’t the Moroccan red clay (which is tan and, shockingly, turned out tan in the soap). Red Sandalwood powder made a really beautiful maroon red. I added a bit of activated charcoal to the indigo root to create a slightly darker blue.

Details and usage rates for this batch:

  • Activated Charcoal (dispersed in sunflower oil) – 1/4 teaspoon added to the indigo soap
  • Indigo Root Powder (infused in olive oil) – 1 teaspoon per cup of soap
  • Moroccan Red Clay (dispersed in distilled water) – 2 teaspoons per cup of soap
  • Red Sandalwood Powder (dispersed in distilled water) – 1/2 to 1 teaspoon per cup of soap


Batch #3 – Alkanet Root, Annatto Seed, Paprika, and Spirulina


Okay, this soap is probably tied with the first one in the ugly department. I didn’t plan my color combinations very well. But, again, I got some good information out of the test. A pretty soap would have been nice, too. Oh well.

Details and usage rates for this batch:

  • Alkanet Root (infused in olive oil) – 1 teaspoon per cup of soap
  • Annatto Seed (infused in olive oil) – 1.5 teaspoons per cup of soap
  • Paprika (infused in sunflower oil) – 2 teaspoons per cup of soap
  • Spirulina Powder (added at trace) – 1 teaspoon per cup of soap

I’ve had experience with all of the herbs and spices in this test, except for Spirulina. I really don’t like Spirulina. It must be added as a powder to get that dark green and it comes out speckled. I tried dispersing it in distilled water first and, man, did that stink. It does produce a pretty green color, but it doesn’t hold up well and will eventually turn brown. I also tried an infusion with it but ended up with a pea green color I didn’t like. My main takeaway from this soap test is a better usage rate for Alkanet Root. Out of a fear of ending up with a gray soap, I’ve always just used too much Alkanet infused oil to get a dark purple. In this test, I used a bit less and got a beautiful lavender color. As always, the Annatto seed imparted a lovely yellow color.

Thanks for reading my post!


18 thoughts on “Testing New Herbs, Spices, & Clays in Cold Process Soap

  1. I think your first soap is the prettiest! I tried red sandalwood but I got a pale beige! Though I had used a lot. Strange. The Infusion was a gorgeous red, but the soap was common. I shall try again! Thanks for that interesting post!


  2. When you create an infusion do you put a teaspoon or so in so many ounces of an oil then heat in a crock pot. Following this can this be saved and used later? I have many powders and haven’t used them much


    • Thanks for reading my post! With most of my herbs, I normally put 2 tablespoons into 5 ounces of oil. However, with indigo root powder, I use 2 teaspoons in 4 ounces of oil. I shake the mason jars up really well, then put them in a double boiler with water just below 1″ of the top and allow them to sit on low (smallest eye) for 2 hours. I let the jars cool completely in the water before removing them. I strain the infusions either through fine netting or many layers of damp cheese cloth. I still find I end up with a big layer of herbs and spices on the bottoms of the jars. But as long as I don’t shake them, I never get any gritty bits in the soap. Most of mine are used up fairly quickly in making soaps, but I have had a couple that I didn’t use much and they were still good at 6 months. :)

      Liked by 2 people

  3. Hi Holly! I am super excited to find your blog! You have so many amazing soaps. I have been practicing making soaps and learning basic soap making over the last few months and decided I wanted to use natural colorants rather than purchase synthetic types. I have been experimenting lately and having so much fun! I am going to start doing some oil infusions so your blog is so very helpful. I have tossed just a few different things into the batter to see its affects. Indigo/henna made a very nice green that was not gritty at all. Turmeric produced a great peach but was gritty. Anyway, thank you for sharing! You have such amazing soaps and really wonderful blog and videos!


    • Thank you, Jacqueline! Experimenting with natural colors really is a lot of fun. I’ve never tried henna powder but will definitely look into that. A pretty green and a true red are the two that seem to give me the hardest time. Thank you for sharing your info and for your sweet comments. :)


  4. I have watched the You Tube Video a half dozen times for the Teardrop Swirl you did! It’s just lovely.
    I have two questions: what was your soaping recipe so that the base will be the correct color, and
    how do you do the calculations to account for the extra olive oil from the color infusions? For example, if all of the colorant-infused oil adds up to 1/4 cup or whatever, do you subtract this from the amount of olive oil in the recipe? I’m new at coloring soap and you’re my new mentor for that as your colors are so subtle and calming. Thanks so much.


    • Beth, thank you! And thanks for watching my video. For the Teardrop Swirl, I modified one of my slow-tracing recipes that I had previously used for the Ebru soap challenge. You can see the recipe I modified here in this post – https://kapiamera.wordpress.com/2015/06/17/ebru-soap-challenge-for-amy-wardens-soap-challenge-club/ I simply reduced my olive oil to 42% and upped my Avocado to 8%.
      As far as coloring my soaps with infused oils, I made a video on how I replace an oil and also how I just add a bit of infused oil to a soap (and below that video I added a lot of links to blogs and helpful sites on using natural colorants). You can see that video here – http://www.youtube.com/watch?v=n0UL2xSrIyI
      I will usually decide to replace the oil when I need to add more than 2 tsp infused oil per cup of soap to get a specific color. For the tear drop swirl, I only used a small amount of the infused oil, so I didn’t worry with substituting. Sometimes I will also add more of the herb to the infused oil to create a darker color. I just make sure I never add so much that the soap will be irritating to the skin. Some spices (like Paprika for example) can be very irritating if used in high amounts. Thanks again and good luck. :)


  5. I watched your video…it was great! When you added the infused nettle to the olive oil that you kept aside, how much of the infused nettle did you add to that olive oil, or did you infuse that batch separately?

    Thanks so much!


    • Hi Kim, Thanks for watching my video! I’m thinking you are referring to the video where I colored the soap green with an indigo hanger swirl in the middle. If I’m wrong about that, just let me know. The olive oil is infused with nettle leaf powder ahead of time (2 Tbsp for every 4 oz of olive oil – I also have a video on how I do that in case you’re interested) and then that infused olive oil is used in place of plain olive oil in the recipe. After I decide what percentage I want to substitute, I then subtract that amount from the regular olive oil in the recipe and replace it with the nettle leaf infused olive oil. Hope this helps! Let me know if I misunderstood your question though. :) –Holly


  6. Holly! I can read your blog and watch your videos for a whole day. You combine art and soap science so great. Your soaps are beautiful!!! I’m enthusiastic how you use only natural ingridients including natural colors in soaps in artistic way. I do my own natural cosmetic and with your huge help I will do soaps on much higher level as I did in the past. It’s a challenge for me, but your soap creations inspire me that I’ve desided to try some of your recipes.
    Thank you again for sharing your knowledge, talent and wealthy experiences!


  7. Greetings Holly,
    Thank you so much for sharing and most of all for your time. :-)
    Your creativity is such a pleasure and inspiration.

    Kind regards,
    Houston TX


  8. Pingback: Rainbow Layered Soap | Kápia Méra Soap Company

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