Brown + brown + yellow = purple?

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Silver

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Hello soapers!

I wanted to make a woodsy type of soap and decided on tiger stripe concept with two shades of brown (brown iron oxide and cocoa powder) and yellow (yellow iron oxide). After unmolding my creation the next morning I was in for a surprise - its about as purple as it gets! Im not sure if the color will fade with time to be brown, so I will be keeping an eye on it. Has this ever happened to you?

Also, for some reason the soap kept warping on me when I tried to cut it with a blade. This has happened to me once before with another hard bar and I am curious what I can do to avoid it - should I use wire cutter instead, should I cut it sooner? I ended up beveling it to make it nice and flat, but in the process I lost quite a bit of soap.

Many thanks!
Silver

purple 1.jpg


purple 2.jpg
 
I've never seen brown turn purple like that, what did you use for scent? Add any other ingredients? I've had warping like that when I used to use more water in my recipes. Reduce your water some, it should stop the warping.
 
Oh, the water! I would have never thought of that. Its true - both of those recipes used full water whereas most of my other recipes use water discount. Thanks!
This recipe was a very ambitions one so it had more additives then usual. I used 1 tsp honey, dual lye (95 : 5) and 5% stearic acid (it was high tallow so I wanted to see if it would help with soap scum). The scent was Himalayan and Texas Cedarwood for the majority of the bulk and some dark patchouli and Palmarosa. The basic recipe was tallow, palm kernel oil, coconut oil and castor.
It also set up surprisingly quickly - within 10 or so minutes it pretty much solidified, even with full water. Thankfully I had just enough time to pour most of the soap in and layer it.
 
Stearic acid doesn't help with soap scum, if anything it might make it worse. You are pretty lucky you were able to use it at 5% and still do CP, it can cause instant saponification/seize.
None of the EO's should have went purple, did you get your oxides from a soap supply company?
 
I'd almost bet the purple is mainly from your brown iron oxide. Lots of darker colors, browns and blacks, seem to have purple bases to them (must be some weirdity involving molecule shape and light scattering), which becomes visible when the pigments are used at a low rate.
 
There are some brown oxides that have a purple base, but I have never used the ones from ND. Just like red oxides there are many different bases. It is possible your color could still morph into a brown color. I was just reading on their page and they do not state it is stable in cp, but there is one review that states they got a nice chocolate brown. Was it a deep brown when you first used the oxide? I do find it a bit odd it turned such a true looking purple even if it was a purple based brown oxide. Will be curious to know if it morphs back to brown and if not I wonder if it is why they are discontinuing it. It could simply be an un-stable brown that varies considerably with ph since not all soap batter is the same ph due to oils used, water/liquid etc.
 
Iron oxides can provide colors as blacks, brown, purples and reds. As Kittish said, I think the brown oxide may have turned purple. 5% citric acid is quite a lot, it can change the pH of the whole batch. As this oxide was meant for soapmaking, it is possible that it turns to another color at lower pH. Oxides are generally stable, but not always. I'm not sure vanillin could by itself be so bright in this recipe.

Anyway, lucky you: this color change is actually very nice!
 
Hey guys,
Here is an update on my soap. Unfortunately the color did morph, and now the cocoa powder portion of the soap is brown. However, the iron oxide mixed batter still remains somewhat purple! I will try to use the oxide at even lower percentages next time to see if I could get a lighter purple color, and will also see if I get the same effect without the citric acid. Thanks to everyone for demystifying this one for me!
Silver

IMG_20170920_223456.jpg
 
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