Plain soap turning purple

[Muskette]

What kind of water did you use?

 

[chachalaca]

What kind of water did you use?

The water that I used is regular purified drinking water (not from the tap, not distilled).

The exact recipe (without compensating for taking away the fragrance and colour solution = very purple bar):
Ingredient QTY (KG)
Water 0.54
Lye 0.25
Soy oil 0.533333
Palm oil 0.433333
Coconut oil 0.433333
Beeswax 0.03
Shea butter 0.015
Cocoa butter 0.015
BHT 0.0012

The exact recipe (compensating for fragrance and colour solution = very very light purple bar):
Ingredient QTY (KG)
Water 0.673
Lye 0.25
Soy oil 0.533333
Palm oil 0.433333
Coconut oil 0.433333
Beeswax 0.03
Shea butter 0.015
Cocoa butter 0.015
BHT 0.0012

Yes, please post the entire recipe, including NaOH, water, additives, and fragrances in weights. This is the only way we can troubleshoot it for you.

This are the two recipes I used:

1.Without compensating for taking away fragrance and liquid colour (very purple bar):

Ingredient - QTY (KG)
Water - 0.54
Lye - 0.25
Soy oil - 0.533333
Palm oil - 0.433333
Coconut oil - 0.433333
Beeswax - 0.03
Shea butter - 0.015
Cocoa butter - 0.015
BHT - 0.0012

2. Compensating with water the equivalent weight of the fragrance and colour I took away:

Ingredient - QTY (KG)
Water - 0.673
Lye - 0.25
Soy oil - 0.533333
Palm oil - 0.433333
Coconut oil - 0.433333
Beeswax - 0.03
Shea butter - 0.015
Cocoa butter - 0.015
BHT - 0.0012

 

[Steve85569]

Does this soap zap?!?
I get a -10 SF using PK flakes when I put this into soapcalc. Something doesn't jive.

 

[Susie]

I don't know why it is turning purple, but I know it is -14% superfat. So it is lye heavy. I would not use this for a very long time. I would also strongly suggest that you make no smaller than 500 gram batches of soap, as very small weighing errors create big bad impacts on smaller batches.

I am assuming you are using BHT in an effort to avoid rancidity in oils, but I have no idea what effect it would have on soap. I also would not use soybean oil, as you are not adding anything good to the soap with it, and you are raising your risk of DOS.

I would NOT zap test this for a LONG time.

Does this soap zap?!?
I get a -10 SF using PK flakes when I put this into soapcalc. Something doesn't jive.

Use palm oil for the calculator. I got -14% SF.

 

[chachalaca]

Does this soap zap?!?
.

What does this mean? Sorry, I'm not familiar with the language yet...

you are raising your risk of DOS.

I would NOT zap test this for a LONG time.

What does DOS and zap test mean? Thank you

 

[Susie]

DOS= Dreaded Orange Spots- soap going rancid and stinking with distinctive orange spots.
Zap test= Touching wet finger to soap, then to tongue to see if soap is lye heavy. Your soap IS lye heavy. No need to test.

Acronym and abbreviation thread: http://www.soapmakingforum.com/showthread.php?t=51841

Zap test guide: http://www.soapmakingforum.com/showthread.php?t=30690

ETA- You really need to learn to use a lye calculator of some sort. This is my favorite one currently: soapee.com

 

[The Efficacious Gentleman]

Did you come up with this recipe or is it from somewhere?

It's also a fairly large batch. I'd go to making 500g to 1kg batches until things are going well and you are more comfortable with soap making

 

[Steve85569]

Zap is a test for heavy base (lye) and from what I can tell the recipe is quite lye heavy.
Susie got it right. I would NOT zap test that. At least not until it has cured for a long, long time.

 

[Soapmaker145]

You have a contaminant in your mix that is oxidizing in the presence of oxygen. Since you didn't use an FO or a colorant, it can come from:
1- the water which may contain a number of minerals (if you didn't use deionized water)
2- the lye which can also be contaminated with minerals
3- your oils. Oils can be extracted using a variety of methods and may be treated with a number of chemicals along the way
4-Your molds

The only way to know for sure is to run some test eliminating/replacing one ingredient at a time. I would start with the water and line the molds with freezer paper. Then I would go down the list.

 

[Susie]

Craig- thank you for catching that it is really large! My math skills ... you can see smoke coming from my ears and hear the gears stripping ...

 

[chachalaca]

Thank you!

Thanks to all the people who are trying to figure this out, I will test all theories and let you know what happens.

The recipe I am using is not mine, is a recipe that already existed and has a lot of problems, evidently.

 

[shunt2011]

Thanks to all the people who are trying to figure this out, I will test all theories and let you know what happens.



The recipe I am using is not mine, is a recipe that already existed and has a lot of problems, evidently.

You need to use a soap calculator and be sure to always run a recipe through it before making soap.

 

[chachalaca]

shunt2011 Thanks for the advice! I'll do that

 

[chachalaca]

I want to let you all know that after a series of different tests I've come to the conclusion that it was an excess of lye probably interacting with the minerals of the water, since I used tap water. I've changed the recipe and they came out beautifully, colors look great and are quite stable. Thanks for your help

 

[paillo]

Nice job of deducing, Craig. Tap water can contain many nasties. For example, you would never want to soap with tap water in this town. http://www.cnn.com/2016/03/03/us/st-joseph-louisiana-investigative-audit/
Just sayin'

 

[Kamahido]

Just my two cents, but my soaps went up in quality DRASTICALLY after I learned how to formulate my own recipes. It didn't really take that long, as most of the recipes you will find online are quite badly formulated.

 

[TeresaT]

Nice job of deducing, Craig. Tap water can contain many nasties. For example, you would never want to soap with tap water in this town. http://www.cnn.com/2016/03/03/us/st-joseph-louisiana-investigative-audit/
Just sayin'

I'm thinking it's safer to drink the water in Mexico City than in St. Joseph. But that's just my unscientific guess.

ETA: Kamahido, funny you should say that. The only epic fail soap I had was from a recipe I got either from a book or online--don't remember which. I did run it through SoapCalc before I made it, but for some reason (and I'd have to check my notes) it never set up. All of my soaps, except that one, have been experiments based on the benefits or qualities of a given fat or oil. I like figuring things out on my own and then asking questions when I get stuck. I'm definitely a "hands on" learner.

 

[Dr.J]

Ingredient - QTY (KG)
Water - 0.54
Lye - 0.25
Soy oil - 0.533333
Palm oil - 0.433333
Coconut oil - 0.433333
Beeswax - 0.03
Shea butter - 0.015
Cocoa butter - 0.015
BHT - 0.0012

I would hypothesize that the BHT is the root cause. It and other phenolic antioxidants, when over-oxidized can form color bodies (quinones) which range from yellow to pink. Pink is especially common in alkaline environments.

...There are times when a high lard will do this...

I suspect this is for the same reason - most lards contain BHT, BHA, and/or propyl gallate for increased shelf life (all are phenolic antioxidants).

A reference about plastic (not soap), but relevant to the topic at hand (esp the paragraph directly under Fig 2):
http://www.ampacet.com/faqs/yellowing-and-pinking-white-pe-pp/

 

[DeeAnna]

Thank you for the info, Dr J. This goes to show "the devil is in the details."