This beautifully marbled soap is a wonderful example of things not turning out quite how you expected, but being wonderful anyways. My working title for these bars was “Indigo Swirl”, but this batch of soap had different ambitions. The particular level of trace in the batter meant the pour-swirl I had planned ended up turning into wispy, marbley seams of blue rather than dancing swirls, and I couldn’t be more thrilled with how everything turned out.
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For this soap I tried something new—a water discount with the intent of eliminating glycerin rivers. When I met Ariane at the Handcrafted Soap & Cosmetic Guild/ Handmade Bath & Body Guild conference in Toronto last June we got to talking about glycerin rivers, and she excitedly told me about a blog post from Auntie Clara about how to prevent them. The general gist of Clara’s discovery is that water discounting means no glycerin rivers, which is fantastic! It’s taken me a while to get around to trying it out, and I figured I’d go all in with a mostly white soap to really test it out. I’m happy to report it worked beautifully! There isn’t a hint of glycerin-river-ing in these bars. Thanks, Ariane & Clara!
I was thinking these bars would be a bit more on the swirly side, but when I cut them open I was excited to see a beautiful marble-esque pattern. I let the weight of the pour do all the mixing in the mold—I didn’t introduce any kind of hanger or pot swirl—and the end result was thin seams of blue batter that really got tossed around by the white batter, creating a beautiful marbled effect.
The blue in the batter comes from an indigo infusion; indigo root creates a stunning blue colour that remains stable in soap. I chose an infusion for a smooth blue colour rather than the speckled look that adding the powdered botanical straight to the batter gives. If you don’t have indigo root, feel free to disperse a pH-stable (no ferric ferrocyanide!) blue mica of your choice in some oil and use that instead.
In addition to the lack of glycerin rivers the water discount gives us, it also creates a loaf that sets up much more quickly than you might be used to. I sliced these at the 24 hour point, which is earlier than I would usually slice soap, and was surprised at how much harder than usual the bars were. I would definitely make sure you make these bars when you know you’ll be available for slicing 24 hours later—don’t make them and then go away for the weekend!
Ensuring your titanium dioxide is very thoroughly pre-dispersed into liquid oil before adding it to your batter will help prevent those little bright white streaks.
Our scent is all peppermint—it seemed fitting for the cool blue, and seems extra fitting with the marble-like appearance. I love marble (surprise, surprise 😝) for its solemn cool touch, and peppermint seems like a perfect olfactory tribute.
I’d definitely recommend watching the video for this soap for a much better idea of how the pour happens—it’s a hard thing to describe well. The video also has the cut reveal, which is always rather exciting! In any event, I’m very happy with this fresh marble-y soap, and I hope you like it as well!
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Blue Marble Soap
25% refined coconut oil (USA / Canada)
25% beef tallow (wondering why?)
45% olive oil (pomace) (USA / Canada)
5% castor oil (USA / Canada)Calculate to 5% superfat with “water as % of oils” at 21.2% (or water to lye ratio at 3:2)
Per 500g fats:
To colour:
- Indigo root infused into liquid oil (as needed)
- Titanium dioxide, pre-dispersed in liquid oil (as needed)
Kick things off by calculating out your recipe for the amount of soap you’re making to get the finite amounts of the fats, lye, and water. Unsure about how to use SoapCalc? I made a video to walk you through it! Please ensure you’re familiar with standard soap making procedure before diving in (click that link if you aren’t!).
Prepare your mould—you’ll want a loaf mould for this soap. Melt your oils together in your soaping pot, and have one container with a pouring spout handy (I use these awesome funnel pitchers). Let your oils cool to slightly warmer than room temperature. Mix up your lye water and let that cool to about room temperature (you can use ice for part of your water to speed up the cooling process).
Lay out your work area so you can easily grab your indigo infused oil, and be sure to pre-disperse the clump-prone titanium dioxide in some extra liquid oil so you don’t have to over-blend the batter to smoothly incorporate it. Prepare your mould by lining it, if required.
Now you’re ready to get started! Begin by blending the kaolin clay into the fats. Once that mixture is smooth, add the lye water and bring to a thin trace. Blend in enough titanium dioxide to get a white-ish batter, and then pour approximately 15% of the batter into your secondary container. Add the indigo infused oil to that batter, aiming for a pale blue colour.
To pour, we want our batter to be just on the thin side of a medium trace. Pour one third of the white batter into the mold, then half the blue batter, then one third white, followed by the other half of the blue batter. Top everything off with the remaining white batter, using your spatula to style the top. The pour is definitely best communicated in video form!
Leave the soap to set up for 24 hours (no longer!) before slicing and leaving to age for three weeks before using. Enjoy!
Hi Marie! Thanks for the new soap recipe. I’m planning an indigo hanger swirl soap and wondered if your indigo colour would have been more prominent if you added the kaolin and titanium after trace and after you separated a portion for the indigo. In other words would the indigo be darker if you added it into the soap batter before adding the whitening ingredients. Anyhow I’m going to try it that way and I’ll let you know! Have a great day! Anne
I think you’re right about the titanium dioxide—it definitely makes things milkier/more pastel hued. Ensuring the blue batter didn’t have any TD in it would likely make the colour deeper. Kaolin clay doesn’t usually impact the colour of a bar too much (especially when compared to TD); I’d think a stronger infusion would make a bigger difference. I look forward to hearing how your bars come out!
I am constantly in awe of Auntie Clara’s soaps. I’m hoping one of these days you’ll attempt her ghost swirl. Great post!
Aren’t they astonishing?! Her instagram feed is like a visual meditation—SWOON. I will look into the ghost swirl 😀
Beautiful soap. I love the lighter shade of indigo and the fact that it looks like marble. No matter how hard I try and weigh out my coloured soap to swirl, it is always too much. I like more subtle swirls like this one you made.
Thanks so much, Lynne! I’ve definitely done my fair share of “whoa, too much!” pour swirls—I usually find a slightly thicker trace and and pouring from a lower height helps 🙂 And luck, of course! Happy soaping!
Dear Marie,
Beautiful soap. I calculated in Soap calc and for 21.2% water as % of oils obtain 106 gr water and 70.7 gr lye(or soda flakes).It is correct? Thanks a lot!
Hello Victoria!
Bang on! Just make sure to remember you are using NaOH and not KOH as your lye! How did it turn out?
I have the same doubt. Is it 7 or 70 gr of lye?
It’s unlikely to ever be 7g of NaOH; that would make a very tiny batch of soap. You can learn how to use SoapCalc here 🙂
Wow, I’ve never soaped that low water amount!
Looks so beautiful Marie, well done! I think I should give a try
You’re inspirating.
Thank you so much, Katalin! It went surprisingly well all things considered—I think the lower soaping temperature helped things from going too quickly. I can’t wait to try this technique with more soaps, and I look forward to hearing about what you create! 🙂
Hi!
Can you tell me how you did the indigo color? Did you use a tea bag or just disperse it in oil. If so, how much indigo root and how much oil? I like your color so I’d like to replicate as much as I can. Thanks and love everything you do!
I’m afraid I really can’t provide terribly precise details as this infusion was leftover from my indigo balm, but from looking at it I knew there wouldn’t be enough so I added more oil and indigo without measuring it. I did use a teabag, though, so it is a strained infusion 🙂
Hi, Im new to soap making. Is there a way to make a pH balanced soap?
Hey! You’ll find the answer to your question in my FAQ Happy making!
Hi Marie! Ive tried this recipe but I don´t know why it doesn´t get white, it changes de color a little bit whiter but is the same color as the oils… can you help me?
Hello Gracie!
Isn’t that what makes soaping awesome? You could have an identical soap recipe being made in China and it also made in Canada, and your end results might be the difference between night and day. How much titanium dioxide did you use for your batch?
There is an important inaccuracy in the description – indigo is obtained from the leaves of various plants (indigoferia tinctoria, isatis tinctoria), not directly, but through a special treatment. Indigo in plants occurs as a precursor, and the pure dye itself is insoluble in water. Indigo root itself will not give a blue color. The link described as indigo root leads to the indigo dye, not the plant root.
Thank you so much, Adam!
thank you for sharing your soap recipes Marie but I have to admit that I’ve had trouble making the blue marble soap…Twice! At thin trace I add the Peppermint EO, stirring with a whisk. From there It seizes right up and I have to glob it in the mold, pounding the mold on the table, hoping for no air bubbles. What am I doing wrong? I used a 33 Percent lye solution which I’ve had good luck within other recipes and calculated it on Soapcalc.