The Ghost Swirl is a technique where a deliberate two dimensional design is ’conjured’ onto the cut surface of soap without the use of any added colourant. It’s not essential whether the design is swirled with a skewer or a hanger, poured or spun, in the pot or in the mould. Essential is only that contrasting shades are achieved purely by manipulation of water content and heat

The Ghost Swirl

posted in: Auntie Clara's Blog, Blog Post, Tutorial | 166


“I had decided to do what I shall call a Ghost Swirl; a technique where a deliberate design is ’conjured’ into the soap without the use of any added colourant. It’s not essential whether the design is swirled with a skewer or a hanger, poured or spun, in the pot or in the mould. The essential thing is that contrasting shades are achieved purely by manipulation of water content and heat.”

I’ve talked about soap challenges before. I like challenges that inspire me to think a little harder, try new things, and push beyond what I do in my every-day soaping. For me it’s less about competing for sponsored prizes and much more about embarking on a personal creative journey, winning insight and experience.

In a Facebook group I run we regularly run challenges and so I know it’s tricky to set the theme for a good soap challenge. If the theme is too loosely defined and the directions too vague, people don’t know what to do with it. If the focus is too narrow (as in “Make an at-least-five-but-no-more-than-thirteen-colour piped soap emulating your paternal grandmother’s second best quilt”) it easily stifles imagination and creativity. Some kind of middle ground usually works best: define a clear framework, but leave plenty of space for interpretation and innovation within that framework.

This week I’m participating in a plain soap challenge. The instructions are clear; no colourant, no fragrance, just plain soap. Milk soaps are allowed.

That’s my kind of challenge, the kind I like; make whatever you like from simple ingredients and let the soap rather than the additives do the talking.

And I love plain soap. A good, well-made plain soap is sexy. It’s not hiding behind any multicoloured veils, it’s unapologetically naked in all its beauty – and begging to be used, not put on the mantle piece. No soap is better suited for showing off shape, texture and detail from a beautiful mould, and stamps seldom look better than they do on plain soap.

_DSC9108 (2)Plain: oval soap on my handwoven linen towel
Plain: Milk & Silk facial soap
_DSC2428Plain: my soap on display at the Louvre in Paris
Buttermilk Baby Handcrafted Soap by Auntie Clara'sPlain: Buttermilk Baby soap


Now, this being a challenge I wanted to challenge myself and do something I hadn’t done before. I’ve done a lot when it comes to plain soap, plain soap and I are great buddies and hang out regularly, so this had to be plain soap with a twist.

As I was thinking about what I had done before it occurred to me that a year ago, while I was experimenting with water discount as a design tool (you can read about those experiments here), I had tried titanium dioxide (in the glycerine river experiments that you can read about here and here), mineral pigment and plant pigment. But I had never tried it without any colourant at all. In this present challenge I was allowed milk, but for my purposes milk would just be another colourant and I now had my heart set on trying my water discount technique without any colourant at all.

I had decided to do what I shall call a Ghost Swirl; a technique where a deliberate design is ’conjured’ into the soap without the use of any added colourant. It’s not essential whether the design is swirled with a skewer or a hanger, poured or spun, in the pot or in the mould. The essential thing is that contrasting shades are achieved purely by manipulation of water content and heat.

For this project I wanted to make a design with very fine lines and details to show off the contrasting shades. I chose a modified mantra swirl (which is what I used to call this type of swirls when I first started doing them long before I had ever heard of a Taiwan swirl 🙂 ).

To make a swirl with fine detail I needed a nicely fluid soap batter and so I began my project by choosing an oil formula that would not accelerate trace – even when mixed with a highly concentrated lye solution. I settled for a 1kg batch of avocado oil, castor oil, cocoa butter, coconut oil, olive oil and rice bran oil (in alphabetical order). Once I had decided on the oil formula I calculated the lye and divided it in three equal parts for three lye solutions. Two of the solutions I made to the strength of 44% NaOH and 56% water and one to the strength of 30% NaOH and 70% water. Then, I let all three solutions cool down to room temp.

_DSC2876 (3)

Big difference in water content there. All three solutions in the picture contain the same amount of NaOH, but you can see from the volume that the solution in the middle has more water than the others. (The droplets on my plastic counter top cover are not lye solution, they are plain water from the outside of the containers that had been standing in cold water to cool down 🙂 )

I melted my hard oils and added my soft oils. I carefully stickblended everything in a big bowl and divided the oil mixture by weight into three equal parts.

While the oils were cooling down to room temp I lined my mould and inserted two dividers.

_DSC2873 (2)

Once everything was room temp I added the lye solutions to the oils and blended each of the three batters to very light trace. The low water batters were poured in the side compartments of the mould and the high water soap was poured in the centre. I then pulled out the dividers and used a skewer to make a fine swirl. I was way too focused on my pouring and swirling to take any in-between pics, sorry about that 🙂


The Ghost Swirl by Auntie Clara's

In this pic the soap is freshly poured. You can see how the high water soap from the centre section is lighter in colour than the low-water soap from the sides. This is typical in raw soap batter. I assume the water droplets suspended in the emulsion reflect more light than the oil does. The more water in the emulsion, the lighter the colour.

Once the soap had set up slightly (the soap was still glossy, but didn’t move when I moved the mould) I transferred the mould to my pre-heated 60C ( 140F) oven.

These are three phone pics ( these are pics for my personal records, please excuse the bad quality) of the soap in the oven. You can follow the gradual change in colour.

The Ghost Swirl by Auntie Clara's
Here the soap has just been transferred to the oven; still wet and the high water soap clearly lighter than the low water soap.
The Ghost Swirl by Auntie Clara's
Here the soap has been in the oven for 45 minutes. The low water soap is light in colour and the high water soap is darker and moving into gel.
The Ghost Swirl by Auntie Clara's
After one hour. The high water soap is now in full gel. Note how the centres of the ’leaf’ shapes in the high water soap are lighter than the surrounding high water areas going through gel phase. Some soda ash has developed – no doubt encouraged by my frequent opening of the oven 🙂


At this point I turned off the heat, left the oven light on and went to bed.

Next morning I unmoulded the soap and cut it – first vertically in blocks and then each block horizontally.

This is what I got:

The Ghost Swirl by Auntie Clara's
The Ghost Swirl by Auntie Clara's


The Ghost Swirl by Auntie Clara's
The Ghost Swirl by Auntie Clara's


That’s pretty spectacular considering that there was nothing but masterbatched base oils, NaOH and water in this soap.

So how does this work? Why is the high water soap darker in colour than the low water soap?

Simply put the answer is that the difference in water content influences the pace at which the soap saponifies and how the soap reacts to ambient heat. The difference in reaction to ambient heat results in different gelling behaviour which in turn results in a shade difference in the final soap.

Those who have read Kevin Dunn’s book Scientific Soapmaking carefully, will know that (everything else equal) a low water soap goes through saponification faster and enters full gel phase at a higher temperature than a high water soap does. In this case the 60C temperature kept in my oven was not high enough to force the uncovered low water soap to enter full gel phase. The high water soap, however, did go through full gel at that temperature. But, even though the low water soap did not go through full gel phase it probably was fully saponified before the high water soap was.

So, by manipulating the water content I was able to manipulate the gelling behaviour and by manipulating the gelling behaviour I was able to manipulate the relative depth of colour in the final soap. That’s pretty cool.

The Ghost Swirl by Auntie Clara's

I need to point out a couple of things here. The ambient temperature is crucial. 60C seems to be a sweet spot where high water soap gels and low water soap doesn’t. Raising the temperature with say 10C might well change things because when the temp is raised high enough the low water soap will eventually enter full gel too. Whether it will end up looking exactly like the gelled high water soap I don’t know. Exactly at what ambient temp this low water formula (without additives in a batch and mould this size) enters full gel phase I also don’t know because soaping with a big water discount and being more keen on quick saponification than actual gel phase I usually just oven process at 60C. Different oil formulas and various additives like milk (sugar), salt, clay or fragrance may also cause changes in gelling behaviour.

The other thing is the relative difference in strength between the lye solutions. The smaller the difference in water concentration the closer the gelling behaviour of the soaps will be. So, if you want to make sure that the soaps show different gelling behaviour you want your low water soap to be properly low in water. You should, however, never attempt a lye solution stronger than 50%.

What I find particularly fascinating about this Ghost Swirl is that the visual effect is not just two-tone (from gelled and ungelled soap as can be expected); it’s multi-tone. On the one hand you get the difference in shade between the low water and high water soap, gelled and un-gelled soap, but you also get that very interesting dark contour line everywhere were low water soap borders on high water soap.

Ghost Swirl Soap by Auntie Clara's

Exactly why that line looks as dark as it does (it’s well darker than the gelled soap in general) I don’t know. My guess is that the temperature fluctuations on each side of that border line (by the time the high water soap is reaching its heat peak, the low water soap is already well in the process of cooling down) cause continuous pressure and tension changes which result in a crystal structure different from either the main portion of the low water soap or the main portion of the high water soap. Different crystal structures will reflect light differently and therefore look different.

The Ghost Swirl by Auntie Clara's

The fact that you can make well-defined designs and swirls inside soap without any colourant is pretty cool, but once again the most interesting thing here may well be the way the top looked when I unmoulded the soap the next morning.

The Ghost Swirl by Auntie Clara's

The Ghost Swirl by Auntie Clara's

As you can see there’s a good coating of ash on the surface. And not a single speck of that ash is on the low water soap. That’s interesting.

Let’s recap: both the high and the low water soaps have an identical oil formula and superfat, both soaps were poured at light trace and both spent equal time uncovered in the same ambient temp in the oven. The high water soap, now covered in ash, went through full gel phase and the low water soap, now free of ash, didn’t. I don’t think full gel phase as such increases the tendency for ash to develop, but it doesn’t seem to prevent it either. The significant difference here is the water content and the ash development is exactly in line with what I’ve observed before: everything else equal ash seems more likely to happen on high water soap.

The Ghost Swirl by Auntie Clara'sVertically cut blocks waiting to be cut horizontally. Nice wood grain effect! 🙂

166 Responses

    • connie

      absolutely genius….two questions: A, where can I join your FB group? B, about the soap…Could you have mixed the two low water/lye solutions into one container, or do you think that would have thrown things off a bit? you are my favorite soaper! when I grow up in my soaping skills, I want to be just like you!

      • Clara

        You could definitely rationalize the method here. You could e.g. make one batter, divide the batter in three and then carefully add more water to one. You need to be careful though when adding plenty of water to a batter you want to keep very fluid; if the water is not the right temp you may easily turn your soap into pudding long before you want to.

  1. Claire edmunds

    This is a fascinating read. I read your other posts about manipulating water content to achieve different colours, but hadn’t thought of trying with a plain soap. The result you achieved is absolutely stunning! I also love soap challenges as they really push me out of my comfort zone and my competitive nature always means I try my hardest. Which challenge was this for please? I would love to go and have a look.

    • Clara

      Thanks – glad you liked it. This was for a challenge in the Soapmaking With Natural Ingredients Forum -group on Facebook.

  2. Joanne Rochon

    Facinating. I love reading about the science of the craft. Beautiful soap. Thank you for sharing.

  3. Debbie

    What a great idea, Clara! The soap looks stunning ….. I’m also a sucker for a natural looking soap, so this is my kind of bar. Although I usually do everything in my power to avoid gel, I may just NEED to try CPOP now!!!

    • Clara

      I think it goes to show that there’s a time and place for everything. If you treat gel with respect and are able to control it, it can work in your favour.

  4. Donna Lee Karlson

    Stunning soap (as always)! I can’t thank you enough for your sharing your creativity, experimentation and scientific insights! Your are an phenominal source of inspiration and an exceptional role model!

  5. Joy

    Love the soap!! Thank you again for this lovely soap experiment, I always look forward and enjoy reading your posts.

    • Clara

      Thanks! I try to explain things carefully and I’m afraid it often gets longwinded; I’m glad you still enjoy it! 🙂

  6. Danee

    I DO NOT SOAP and yet I read every single word you post…in fact your blog is one that as soon as I realize you have posted, I head over and start devouring every word. My adoration for your work stems from a variety of factors. The first time I stopped over to visit it was purely because of your gorgeous soaps. Your work is just too beautiful not to inspire my artistic side. But I keep coming back to visit because of your words, your love of experimentation and how you play within your craft. Your need to keep pushing the envelope of soaping and your willingness to ruin a batch or two in the name of learning just does something to my creative side. One of the worst outcomes of this new “Instagram World” that we find ourselves in is the unwritten- but deeply entrenched- rule that we can only show perfection. We aren’t allowed to talk about unhappy moments, real life, or mistakes. Every moment we share is uploaded only after we have tweaked it to perfection and added a filter or two. But real life IS messy and growth IS messy. If we only allow ourselves to work within the boundaries of perfection we can’t grow and learn as individuals or as artists. Sometimes we have to make a batch of soap that looks more like a candy brittle than a beautiful bar of soap in order to advance our skills. You are so willing to make that brittle bar and then keep pushing the envelope further and further until you understand it all and then you take control and bend the soap to do what you want. The Ghost soap is divine and so sublime I can barely stand it. Just pure soaping perfection.

    I am fascinated at your attention to detail in every experiment you undertake.

    • Clara

      I’m glad you like it but I so don’t understand it all 🙂 I don’t and that’s what makes it interesting – there are always new things to learn and discover and it’s a fascinating journey. The day I have figured it all out I’ll most probably be done with soapmaking 🙂

  7. anyaika

    Thank you Clara, it’s really amazing. I am also fond of natural soap without any artificial stuff, so I felt the urge to try it when I saw the very first pictures. I’ve read it through several times, but there’s one point I cannot understand. You write, you divided NaOH into three equal parts. If I am not mistaken, it means that the SF ratio must also be equal in each “layer” of the soap. The only thing you altered between them, is the amounts of water. If it is so, what do you mean by the percentages (44%-56% and 30%-70%)? Let’s say, 1000g of oil mixture requires some 380 g of water alltogether. Divided it into three, you get 126.67g. How should I “move” this to get the percentages that you mentioned? Thank you in advance!

    • Clara

      Don’t look at the oils. The percentages describe the concentration of NaOH and water in the lye solution and do not refer to the oils in the formula. Say that my total NaOH for the batch was 300g (which it wouldn’t have been for a 1000g batch of oils, but let’s pretend), then I would have had three portions of 100g NaOH each. In the low water solutions that 100g would have made up 44% of the total lye solution. In the high water solution the 100g would have made up only 30% of the solution because that solution contained more water. Hope this makes sense.

      • Cathy Gordon

        fyi the formula for calculating the water for the lye is 100-x/x so if it was the 44% low water solution it would be calculated 100-44/44 which equals 56/44 or 1..272727 you would then multiply the amount of lye you are using by this 1..272727. Just so you know it took me 2 hrs to figure this out. LOL but now I am set. I can vary the water to lye ratio to anything. I want now

        • Clara

          There you have it! Essentially the fork for your lye concentration is between 1:1 water to lye and 3:1 water to lye. The bigger you want the difference in gelling behaviour, the closer to the extremes you pick your values.

      • anyaika

        Thank you very much, Clara. Absolutely clear. I overcomplicated it a bit. But this relatively high concentration of lye solution frightened me at first sight.
        I guess that doing nothing with the water amounts but putting some sugar or honey in the middle row would do something similar: it would also influence the gelling of the layers, wouldn’t it? I must try… :)))
        Thank you once again, Clara.

        • Clara

          It might well, but exactly how much sugar you need to bring up the temp enough is guesswork, you’ll have to experiment and take good notes. Just remember that your low water soap is more resistant to overheating than your high water soap is; forcing gel in a 60C oven on a soap high in water and high in sugar may cause cracking and separation. If you add sugar to low water soap – as you suggest – you stand a better chance of avoiding those issues. I did some experiments with overheating – you can check them out here

  8. Brenda B.

    I too love a beautiful bar of plain handcrafted soap! This soap you created is a work of art! So creative, so scientific! Clara you are an amazing soap maker. Thank you for sharing. 🙂

  9. Joan

    Absolutely interesting reading! What beautiful soap….anything but plain. I have heard Kevin Dunn speak several times before at soap conferences. He would love your theories.

  10. Joan

    I know you have recently visited the US from your blog,..but if you’d like more information on the annual Soap Conference he usually speaks at, you could contact me privately. The one day might happen.

    • Clara

      We had a fantastic, epic trip to the US! Unfortunately though, that means that the ‘travel to the US’ budget has been spent for the next few years 🙂 But to one day be able to attend your soap conference would be wonderful.

  11. Pam

    Fascinating study once again Clara thank you for sharing. You can get a similar effect in color by dividing the lye and oils in thirds and adding different sugars to the combinations. That said your study is much more enlightening and I appreciate it.

    • Clara

      The beauty of this is that you can combine it with all sorts of things. Add dye or pigment to the equation and you can do this with an added rainbow effect if you want to. You can use this as an additional effect, a ‘shadow’ effect as it were if you combine it with a coloured swirl. Etc, etc.

  12. Beth

    Thank you so much for sharing your experiments and your knowledge. I love learning, and trying new techniques. Sometimes, understanding the “why” seems beyond me, but your way of sharing information certainly helps. Now I want to play, too.

    • Clara

      To me, the more you know, the more interesting it gets. Since this is what we do we might as well try and understand as much as possible about it. Happy playing! 🙂

  13. Kerri

    Seriously – you are a true artistic genius. Absolutely lovely – thank you for sharing and walking us through your thought process and creative process!

  14. Jo

    Thank you so much for writing this blog. You are so inspiring in your experimentation. One question I have is about cold process. You made this soap with hot process. I love cold process soap and so I am wondering if you know if it would work with cold process as well. Or maybe I just need to experiment!

    • Clara

      Normally I would define hot process as a method where an external heat source is used and the soap is moulded after saponification is done. In cold process the soap saponifies in the mould which technically would make this cold process – even if the moulded soap is the kept in a heated oven. But, that’s semantics. You would like to know if this effect could be achieved without any external heat source? I think it can. If you use a 1kg log mould like I did you are likely to be able to get the high water soap to enter full gel phase without the low water soap entering gel phase provided that you cover and insulate the mould very carefully right after pouring the soap. You want to insulate as soon as possible in order for as much as possible of the heat generated by saponification to build up inside the soap rather than escape. The 60C oven works as a handy alternative to insulation: whether it’s hot summer or cold winter the oven temp is constant and that makes the process more predictable.

  15. Carol

    Your soaps are always so stylish and sophisticated, and beautifully photographed. I really appreciate the detail and explanation you give as to your methods and the theory behind it. As a newish soap maker, your blog has inspired me to try out new techniques and I’m always delighted by the results. Looking forward to trying this technique. Thank you for sharing.

    • Clara

      Thank you Carol! Trying new techniques is the way to go; it’s not just fun, it also increases your understanding of the process. I hope your version turns out beautiful!

  16. Angela

    Elegant suds! I love how your words show your true passion for soap making and the knowledge you have on soap is refreshing to read!

  17. Scottie

    This is such a cool project and I really appreciate the depth of explanation. Keep up the good work!

  18. jeanne

    You are a true Master! I am so inspired by your creations and how you keep challenging yourself to do more! Thank you so much for sharing your great knowledge with us!

  19. LaTonia

    Your soap is absolutely gorgeous. I love it. It looks so classy. Who would have thought to experiment with lye and water solutions in one batch of soap. So inspiring!!!

  20. Kathy

    You have taken the science of soaping and created a beautiful art. I love the white on white effect. As another mentioned, your blog is very well written and so easy to read. I have so much to learn. Thanks for posting!

    • Clara

      Thank you! Glad you find it easy to read. It’s good to know that my writing makes some sense – English is my third language.. 🙂

  21. bbee

    Just briliant! I just love your work.
    I´m a Hobby soaper and your work inspires me!
    I will try the Ghost Swirl as soon i have time left.

    Best Wishes

  22. Irene

    I find your experiments fascinating, your soaps lovely, and your creativity quite wonderful! The thing I am most curious about with the concept of different water amounts within the same bar of soap is this – what happens a year or two down the road as the water evaporates out of the soap? Will the different sections of the soap pull away from each other? Or as you use the fully dried soap will the less dense sections go faster leaving blank spaces in your soap? It would be interesting to see if it makes a difference. Thank you for all you share!

    • Clara

      No, the different sections don’t pull away from each other, but the high water portions will shrink more than the low water portions. On the cut surface of the soap you will see this as more of an indentation on the high water portions. In my experience there is not much difference in how the high and low water portions wear in use once the soap has cured for about sex weeks or so. But, in my glycerine river experiments where each bar was half low water soap and half high water soap side by side, the borderline between the two portions wore down considerably faster than any other part. This happened with every bar in both batches.

  23. Madame Propre

    hello Clara. Thank you so much for your articles, they are always so instructive and inspiring. After reading your previous posts on water contents, I had tried playing around with various patterns creating from various concentrations. Some 6 months down the road, as the soaps are now very dry, they became a little “bumpy”. The different water contents dried differently and as a result some parts of the soap are thinner than others, while the difference in shade has lessened. Did you experience the same ageing process?

    • Clara

      In my experience the high water portions will lighten as the water evaporates and as I said in a previous reply, the high water portions will shrink more as water evaporates and so the low water portions will seem to protrude. Yet, I have one bar of the green batch in front of me and although the green from the plant pigment is no longer very green, the contrast between the darker high water soap and the lighter low water soap is still quite strong. It will be interesting to see what this Ghost Swirl looks like in a month or so – so far it’s looking very much like it did initially. What I do find very interesting about the texture is the fact that it isn’t just the result of more water evaporating from the high water portions over time; there is a clear texture difference on the cut surface immediately, before any water has had time to evaporate (you can see this on the one picture where the freshly cut bar is photographed against the light). I think the different portions expand differently while hot creating pressure and tension differences that are released as the soap is cut.

  24. Kairava

    Oooh at last I have found the time to read and study your blog Clara.
    After my first succesfull experiments in the liquid soap world it is now time to return to bar soaping again.
    And you have inspired me, again!. I have some Red Brazilian palm oils and I would love to try this with that.
    So refreshing your writing and your investigating mind.
    Thank you for your blogs I thoroughly enjoy them and learn with you from your experience.

    • Clara

      Thank you! Red palm oil gives beautiful sunny yellow soap and I’m sure it could look very nice shaded like this.

  25. Debbie

    What a fascinating post and interesting discussion!! Your results are stunning, and the name, “Ghost Swirl,” is perfect. You inspired me to try this technique and share my results in my little blog. Thank you for sharing!

  26. Kirsten

    This is gorgeous! Color me blonde though, I still cannot figure out how after cutting them vertically, you managed to get the cool pattern on each part of soap cutting it then horizontally…?? Maybe my loaf mold is a different size than yours, but if I make a pattern on the top of mine, and cut it horizontally, you would see noting on the bottom bar. Can you please clarify for those of us who are unable to imagine this properly? Thanks so much! BTW, when you go through this oven gel phase, how long do you cure the bars for? What size (ounces) do they end up? Just beautiful! thanks.

    • Clara

      Hi Kirsten! The soap is poured into the mould using dividers, i e the different portions of soap lie side by side in the mould from the bottom of the mould to the top. The swirl is then done through the entire soap, not just on the very top. I.e. you take a skewer and dip it into the soap all the way down to the bottom of the mould. Then you swirl and that’s how you get the pattern throughout the soap.
      Oven-processing soap does not in itself shorten the time that the bar needs to cure to become hard and long-lasting. The only thing that effectively can shorten the cure time is a steep water discount. The less water you add to your soap, the faster the water will evaporate from the soap. I make most of my bars to be just above 100g when cured.

      • Kirsten

        thank you for clarification. It is a loaf mold then? I discount water all of the time, but in something so delicate as this, I might be worried that a discount might make it set before I could get the pattern all finished. So beautiful Thanks for taking the time to answer my question.

        • Clara

          Yes, it is a loaf mould. As always when working with big water discounts it’s a good idea to keep mixing temps as low as possible to avoid extra acceleration of trace.

  27. Kerry Adams

    Beautiful soap. Gave it a try today. Several firsts for me. 1st H2O discount, using dividers, doing very light trace, trying the Taiwan swirl, using oven method. The swirl pattern not perfect, but pretty. High H2O part gelled! Now, just need to be patient. So excited.

    • Clara

      Hi Kerry! I think of the Ghost Swirl as a fairly basic, straight-forward thing, but now that you put it like that you help me see that it actually comes with quite a few challenges for somebody who hasn’t done these things before. Thank you for opening my eyes to a different perspective 🙂 I hope your soap is beautiful and that you learnt some handy things in the process of making it.

  28. Jennifer A Shepherd

    I made this with three layers then a hanger swirl. It turned out beautiful and actually looks like real ghosts in the pattern.
    I’m so pleased I found you. Now to see where I can go from here with this technique. ThanQ so much for sharing this with us all.

  29. Sarah

    This is an exquisite soap. I love it! I started soaping a month ago and have had several fails, which seem to be more than not and several sucesses. I am learning a lot and still trying to find what works for me. I have heard a lot of soapers letting their lye water and oils reach room temperature. But, what is “room temperature”? Given that it is winter and in my cellar, my soaping room temperature is currently 66 degrees fahrenheit. So my question then is what is too cold for room temperature soaping? I have heard of false trace occurring with harder oils and low temps, and have heard the cons of too high temps, then throw in gel phase, soda ash, and everything else in between it makes my head spin! Haha I am looking for that happy medium and less failures. Thank you so much!

    • Clara

      Hi Sarah! You are right, ‘room temperature’ may be a conventional term for something very close to 22C, but in practice the temperature in my soaping room fluctuates a lot with temperatures being above 26C for weeks in summertime and below 16C for weeks in wintertime. So, to determine mixing temps I go by feel – and looks. Feel as in feeling the outside of the oil container and the outside of the lye container. If it’s cold in the room I make sure that both oils and lye feel tepid or barely warm to the touch. In winter this usually means that I need to stand the lye solution in a hot water bath for a while if it has been made the day before. When soaping ‘room temp’ my rule of thumb is that the lye should be the same temp or slightly warmer than the oils in order to avoid hard oils solidifying at contact with the liquid before saponification takes place. By looks I mean that the oil mix needs to be fully clear and transparent. At what temp this will be the case depends on what oils are in the mix, ambient temp etc. If the mix is high in e.g. stearic acid the temp needs to be higher for the oils to be clear than if the mix is e.g. all olive oil and castor oil. If the oil mix is already cloudy and you add cool lye to it you may end up with false trace or just uneven-looking, spotty soap.

  30. Kerry

    Thanks Clara. I never fail to learn something new or get an interesting perspective on soaping when I read your stuff. Made the ghost swirl several months ago and loved it. I think it’s time to revisit that technique. Perhaps this weekend.

    • Clara

      Hi Kerry! So glad you liked it. I’m still fascinated by the fact that it works – and that it works purely on the basis of how coldprocess soap behaves.

  31. Dustin Yoder

    Clara, your soap is inspiring. I am a very very new soaper, having finished Kevin Dunn’s book only a few weeks ago. I’ve begun my initial single oil soap testing and am so overly eager to begin making the “real” thing I can barely stand it. I have been imagining all sorts of designs in my head but the one design I knew for sure that I wanted to try out was a cream and white swirl. I imagined I would be using titanium dioxide alongside uncolored soap to achieve this affect, but now I know I will be trying your ghost swirl technique because the affects are truly elegant and beautiful.

    I wanted to offer a hypothesis as to where the darker line that appears between the high and low water soaps might come from. Is it possible that the water content is attempting to equalize itself? I’d like to use the word osmosis here, but I know that is incorrect as it only pertains to the diffusion of water across a membrane and that doesn’t really apply here. Diffusion might be a better word. The water concentration across the soap is not equal and in its attempt to equalize itself, the water moves away from the highly concentrated areas toward the areas of lower concentration. I’m also going to assume that the low water soaps probably solidified quick enough that it didn’t actually allow the water across the divide so that there was a build up of water along this border. You can see that the center area of the high water soap is a lighter color than the borders and this would make sense if the water migrated from this area towards the low water areas causing it not to gel as completely. So what you end up with is lower water (lightest area), high water (darkest area) and medium water (medium lightness area). At least that is what makes sense to me.

    However, your glycerine river experiment might debunk my theory. A more fully gelled area would not wear away more quickly, but in that experiment you said that this is exactly what happened to the darker area bordering the high and low water areas. Because of this you predicted the same thing for the ghost swirl soap in your follow up blog. I haven’t heard yet if that was actually the case in the ghost swirl soaps. Can you update us?

    • Clara

      Hi Dustin and thanks for taking time to think about this with me 🙂 I think your theory sounds very plausible and the beauty of it is that it should be fairly simple to verify with simple lab equipment: just check moisture level in different areas in freshly cut soap. The fact that the visible differences in shade and hue remain after cure is, I think, an indication that what we see is not the moisture directly, but the internal structure that came about due to a particular initial moisture level in combination with a particular heat development pattern. I still think that part of the explanation to the dark borderlines is tension development between the unsynchronized expansion and contraction patterns in the low and high water soaps. But extra moisture in those borderlines may well be part of the equation too.
      Haven’t really noticed that those borderlines would wear down faster than the rest of the soap. That may be due to the fine swirls with lots of fine lines running parallel. Also, the oil mix in this palm-free soap is generally more easily soluble than the one I used for the glycerine river soaps and that could have an impact too.

  32. Giota Noutsi

    Ηello dear Clara, I’ve gone through your notes several times, but since I don’t have much experience in soapmaking, especially with such techniques, I have some issues with the making of different lye solutions. Let’s say I make 1000kg of oils, How will I make the two different lye solutions? What water ratio shall I put in the soap calc? And how will I split that in 3 parts? If you find this comment too annoying, pls don’t replay. Keep on the inspiring job you do.,

    • Clara

      Hi Giota,
      This may be the easiest way:
      Use SoapClc to calculate the lye for your intended oils (eg 1000g) and superfat (don’t worry about the water on SoapCalc, you can keep the 38% default). Once you know how much lye you need in total you divide the total amount in three equal parts.
      Then the water for your three lye solutions: use e.g. 1.5 times the weight of the lye (one third of the total amount of lye) for the low-water soap. For the high-water soap you can use 2.5 times the weight of the lye. With your three equal parts of lye you can make either two-low water soaps and one high-water soap or two high-water soaps and one low-water soap.
      Once you have your three lye solutions you divide your mixed oils in three equal parts and then you make your three soaps.

  33. Giota Noutsi

    Μy dearest Clara, I was so happy this morning to see your responce!, Thank you so much, all is so clear for me now, I only have to try it, and see what happens! I’m very optimistic though thanks to you. Your soaps are such an ispiration, you are on the top of my beloved soapers list! Have a wonderful day, mine will be for sure! If you ever want to visit Greece, I’ll be glad to have you over my home!
    Looking forward to seeing more inspiring soaps from you,

  34. Andrea

    So, i tried this last night….hmmm, left me thinking. I was very careful to not overblend and then found that the high water soap accelerated so much faste than the low water soap….i ended up with the low water soap just emulsified and too liquid to maintain its shape (so to speak) to make good pattern. Byt despite this it came out really nice. I will tive this soap to some of my friends with sensitivities. Thanks for sharing this. Of course this leads to more questions….but i suppose that’s why making soap is so much fun and so fascinating….

    • Clara

      Lots of eye-opening things in this project – for me too. Interesting for instence that your high water soap accelerated faster, the recommendation being that one should use more water if one wants to avoid acceleration. Now to try and figure out why that happened and you’re on to a new and different story 🙂

  35. Diane

    This soap is intriguing and beautiful. I have been making soap for 20 years and your explanation makes sense to me. I just read a recipe that you don’t check temperature of the lye, you just put in your oils,and the lye will melt the oils. It just seems a bit risky to me to do this. I am still striving for the perfect bar of soap.

    Diane. Fellow soap maker

    • Clara

      Hi Diane. The heat transfer method works well if your batches are large and your hard oils aren’t super cold. In winter my indoor temperature here is 16C. If the batch is small the bowls and utensils are going to absorb so much heat that your hard oils may not melt properly. I’m also striving for the perfect bar of soap 🙂

  36. Lev

    Very elegant soap.
    I am learning to make soap and I wish I can learn from you in my country.

    • Clara

      Thank you! Inspiration and curiosity know no borders – just keep on being interested and curious and you will learn lots.

  37. Erica

    Ok. Would it be ok just to make two or three small batches of soap with different levels of water concentration?

    • Clara

      Of course. No need to stick to my exact method here; I’m sure you can do an infinite number of variations on this with some stunning results. I ‘masterbatched’ my oils in order to eliminate all other variables than the water content for my experiment, but you could also use different oil mixes in the different portions and see how that affects the end result. There are no rules so you can play with it as you like.

  38. Karen

    Hello, Clara!
    I haven’t ever made soap, but I hope to. Clara, this soap is so very beautiful. If I can ever make a soap half so lovely I will be very, very happy. Thank you. You inspire me!

  39. Mayra Rojas

    Hi Clara!! I’m from México City and I really admire your besutiful work!! I’m a soaper since 3 years ago and I really learn a lot when Read your post. Normaly latin American soapers use “Mendrulandia Calc” and it’s diferent in many terms if compare with “Soap Calc”
    Sorry about my English!! I hope you understand!! Talking about The watter in this case, difference between more or less watter is only “concentration right? Do you know Mendrulandia Calc? Can you see it and tell me something about it? I usually maje a soap with 30 concentration
    Maybe I have to play with that and see what happen
    A lot of kisses from Tequila land

    • Clara

      Hi Mayra. I just had a look at the Mendrulandia Calculadora and the ‘Concentración’ is the concentration of the lye solution, ie NOT the water as percentage of oils like in SoapCalc. On the Mendrulandia Calculadora my low water soap usually has a ‘Concentración’ of around 40%. I also noted that the default superfat (Sobreengrasado) is 8%. That’s fairly high. I usually stick to a 5% superfat and make sure that my oil mix is low on cleansing power.

  40. Celebrant

    Awesome!!! That’s all I can say.
    I need to subscribe to your News llLetter, I looked for the link but couldn’t find it. Give me pointers pls.

  41. Tina Westover

    All I can say is WOW! That is such a beautiful soap and so interesting how you achieved it. I am brand new to soaping, only have 4 batches under my belt (one of which went in the trash due to being lye heavy) so I can’t imagine ever being good enough to pull something like this off! I have dreams of creating stunning soaps that I can sell one day but when I see other soap maker’s beautiful masterpieces I wonder how I would ever be able to compete! I think I might have fun trying though and maybe one day I’ll have a masterpiece to show for it. In the meantime I’ll enjoy looking at yours!

    • Clara

      Thank you! With enough determination, practice and curiosity you can pull off almost anything. Happy soaping – keep it up!

  42. Jay

    Amazingly beautiful…wow…. wow… Thank you so much for sharing
    I have not been soaping for over 2 years but always been enjoying watching the experts’ soap making in Youtube. This wonderful technic truly inspired me to do it again very soon. Thank you so much.
    Shame on me .. I bought Kevin Dunn’s book in December but not yet finish reading yet. Meanwhile I did have infused 26 different kinds of herb in olive oil with cold infused method (to preserved the quality of herbal benefits), Not particularly in joy with all the vibrant coloring when I was soaping. I’ve been thinking about (not yet try it) creating a similar natural swirl effects by mixing the herbal infused and non-infused oils, without any added coloring. Now if applied with your Ghost Swirl, certainly there will be a lot more possibilities to the natural coloring and design in my future batch.

    Thank you again.

    • Clara

      The Ghost Swirl certainly adds an extra dimension and since it’s a technique or method rather than a strict design you can apply it in lots of different ways – and learn about the behaviour of your infused oils in the process.

  43. Andrea

    I love ‘just’ soap! I thought I was the only one!
    Can you share a link to your Facebook group, and can I join you?

  44. Kelley

    I have seen the ghost swirl but now I have read how it was created and seen your work of it, I have to try it. It’s so beautiful and artistic but staying true to soap our grandmother made (kind of!)
    This is a perfect time for me. I have been doing lots of colourful soaps with swirls and just recently I made a plain soap with pink clay on the bottom, cocoa pencil line and the top was the natural green of the avacado oil I used. It just looked wonderful. I was wondering just the other day if I could incorporate different types of soap in one. Coconut oil, avacado, and yellow olive with Cocoa Butter to see what I could do with it. A colour variation with no colour, even natural ones added. Do you think it would work or would it be a mess?

    • Clara

      I’m sure it can work if you plan it well. Gelled and ungelled portions of all those oils should look interesting. And why not try them all once ungelled and once gelled. Sounds like exciting things to try.

  45. Sharon

    I MUST try this – so cool!!! I think I will also then try it with a single color (maybe mica??) to see if that causes any change…. Thanks so much for sharing your info!!

  46. Susan pollak

    Hi. I love your soap – very beautiful. I have a question – my oven will only start at 170. Is there anyway for me to do a ghost swirl? Thanks

  47. Diane Silvestri-Clifford

    Love what you do…a true artist.
    Can you add FO or EO to the ghost swirl?

    • Clara

      You can do anything you like with the Ghost Swirl 🙂 It came about because I wanted to see if I could create contrasts and swirls without using any colourant and since many FOs and EOs affect the colour of the soap I chose not to use any scent either in mine. But unless you’re trying to prove a point the way I was, there’s no particular need not to use scent.

  48. Fay

    Gorgeous!! Somewhat new to soaping but so addicted to it already. And love love love your entry on this experiment! Well done!! Question…In your original recipe, did you calculate any water discounts before calculating the water / lye ratio?

    • Clara

      Hi Fay. ‘Water discount’ is actually a misleading term since you need the same weight of water as lye to make soap and any water above that is in actual fact a surplus rather than a discount. ‘Water discount’ is usually a reference relative to the 38% water of oil weight default in SoapCalc. A water:lye ratio is a definite thing: if it’s 2:1 it means that you have 2 parts water and 1 part lye. If you discount the water from your two parts or the lye from the one part you won’t have a 2:1 water:lye ratio. So in answer to your question: no, I didn’t discount either water or lye before calculating the water:lye ratio.

  49. Bin

    Beautiful! Thank you for sharing your experiment with this cool design! You’re my favorite soaper! I’ve learned a lot from reading your blogs, and of course, spent a lot of time staring at your beautiful soaps… lol

    I soap as a hobby, and I just started several months ago. I’m still experimenting with water discount and soaping temperature trying to control gel phase. I don’t like the darker circle in the center of a batch. I’d like it to fully gel, or not gel at all. From my research, my understanding is that heat needs to be preserved so that the soap can reach to a higher temperature needed to gel. So my instinct is to put a batch into a fridge if I don’t want it to gel. I’m interested to find out that you actually put your soap in 60C oven, and your soap doesn’t gel. Is it because you soap with steep water discount? Low water does make gelling temperature to go higher. But if the soap is put in the oven, isn’t it easier for heat to accumulate? Especially in the center due to slower heat dissipation? Even that is not enough for the center to gel? Interesting!! Is it because you soap at room temperature, so the temp is low to start with (comparing generally recommended soaping temperature of 120F for beginners)?

    • Clara

      Bringing up temperature in soap is relatively easy. Soap does that by itself and giving it a little help is easy enough. Trying to bring down temp in a saponifying soap is much harder. To keep heat development under control it’s much more efficient to keep initial mixing temps low than to try cooling down a hot soap after the fact. Refrigeration will bring down the temperature on the surface of the soap, but the hard crust thus created will insulate the centre of the soap effectively resulting in partial gel in the centre of the soap. Making use of the thermostat in an oven on low heat actually helps heat management: if the soap starts heating the oven the thermostat will kick in and the oven will switch off and help keep the soap from overheating.

      • Ramana

        I really enjoyed your work, I am really hoping to start soap making just as a hobby, reading articles to understand the chemistry behind. I am thrilled about the plain coloured soap but with variation of colours without adding any artificial additives/ or natural but fades quickly.
        1) the mould be made out of Wood, if so would this stand the 60C heat?
        2) if I add any essential oils or any herbs to while making soaps, would the effect / essence of the herbs will remain the same without being changed by the Lye or the heat produced while you are making the soap.
        Waiting for your response.

        • Clara

          Wooden moulds work well and can withstand 60C. Essential oils and herbs have lots of different properties. Some can take high pH and heat – others can’t so there isn’t a short answer to that question.

  50. Patricia

    The only downside of this soap: it be a sin to use it, it’s so gorgeous. Would you consider doing a tutorial for this technique? Because really, all I got was: complicated, complicated, science…complicated, complicated, pretty…complicated complicated, oven…oooooh….all done!

    • Clara

      This is the turtorial and it really isn’t all that complicated: one soap with plenty of water and one soap with minimal water swirled and then kept warm enough for the more watery soap to gel. And Bob’s your uncle.

  51. Cindy Vassar

    Do you remember where you bought the mold That you used for the soap in the Louvre?

  52. Ajoke Ojo

    I am new to soap making and only just discovered your Instagram page. This is a great blog, very informative for us “students”
    I will obviously come through your archives and read and reread all that you have written!!
    Thanks for sharing this knowledge

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.