EDTA vs Sodium Citrate

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ngian

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Well another experiment took place a week ago, and made three bars with the following recipe:

Olive oil: 30%
Lard: 30%
Coconut oil: 25
Canola 15%

Lye Discount: 2%

Lye Concentration:
Control: 35%
EDTA & SC: 33%

where the amount of EDTA is at 0,5% of oils and SC at 4% of oils.



I had an accident though that only the look of the soaps were affected, and as you can see one bar of the control soap and all 5 bars of the SC soaps have this rustic look.

As I realized that the 4% SC made a softer soap bar after 2 days of curing (maybe 4% is too much or SC tends to soften the soap's hardness), I put the specific rustic bars in the oven while being warm (~65°C) and not in use thinking that I could try and make them a bit harder with the help of some heat. My wife then wanted to cook something, but I didn't had the time to inform her about the soaps, so she turn the oven on to 200°C when after a few minutes I heard her shouting! The soaps were immediately taken out of the oven while the plastic tray was starting to morphing, and the bars went through the gel phase one more time (I had them CPOPed in the first place).

They were so soft like jellies but after cooling outside they became the soap bars they used to be regarding hardness. The SC soaps though are still softer than the other two.

So I will wait a couple of months before I test them.
 
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KristaY

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Recently Teresa posted her thoughts on how the soap felt between these 2 additives so I'll be interested to hear what you think. Thanks for posting, ngian!
 

ngian

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It was only for a few minutes and just before reaching 200°C.

They just melt as they gelled and lost their initial shape.

The white (control) that was in the oven is now just like the other 4 control soap bars that weren't in the oven, regarding texture and hardness, so I guess the same is for the sc soap bars.
 

TeresaT

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I'm excited to hear your thoughts on your experiment, too. You used much more SC than I do in my soaps. I use 2.6% ppo, which is the equivalent of 2% of citric acid. (I do 2% in my CA batches.) When I made my EDTA batch, I only used 0.5%, like you did.

This is where I got my amounts, if you are wondering. I don't know if you have seen this before (it's from a post by DeeAnna). I made a screen shot of this and literally take it where ever I go. (It's on my phone and saved to my cloud.)

BTW: The colors for the EDTA and SC soaps are beautiful. What did you use to get them?

How to use CA, SC and EDTA.png
 

topofmurrayhill

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Use of Tetrasodium EDTA in cosmetic formulations

Baby shampoos 0.05%-0.2%
Baby lotions, oils, powders, and creams 0.1%
Other baby products 0.3%
Bubble baths 0.01%-0.1%
Other bath preparations 0.05%-0.1%
Eyebrow pencil 0.1%
Eyeliner 0.2%
Eye shadow 0.5%
Eye lotion 0.2%-0.3%
Eye makeup remover 0.004%-0.2%
Mascara 0.05%-0.2%
Other eye makeup preparations 0.05%-0.2%
Colognes and toilet waters 0.04%
Hair conditioners 0.02%-0.1%
Hair sprays-aerosol fixatives 0.08%
Hair straighteners 0.2%
Permanent waves 0.2%
Shampoos--noncoloring 0.05% 1.3%
Tonics, dressings, and other hair-grooming 0.04% 0.1%
Other hair preparations-noncoloring 0.05% 0.2%
Hair dyes and colors 0.3%-0.4%
Blushers 0.5%
Face powders 0.04%
Foundations 0.01%-0.09%
Makeup fixatives 0.01%
Other makeup preparations 0.1%
Other manicuring preparations 0.2%
Dentifrices 0.02%
Other oral hygiene products 0.009%
Bath soaps and detergents 0.009%-0.5%
Deodorants--underarm 0.04%-0.3%
Other personal cleanliness products 0.09%-0.2%
Aftershave lotion 0.1%-0.3%
Shaving cream 0.08%-0.5%
Skin cleansing preparations 0.02%-0.5%
Face and neck preparations - not shaving 0.04%-0.3%
Body and hand preparations - not shaving (796) 66 0.04%-0.1%
Moisturizing preparations 0.05%-0.1%
Paste masks--mud packs 0.02%-0.1%
Skin fresheners 0.04%-0.09%
Other skin care preparations 0.005%-0.2%
Suntan gels, creams, and liquids 0.2%
Other suntan preparations (38) 0.08%
Astringents 0.09%
Face treatment 0.2%
Gels - 0.04%
Skin protectants - 0.04%
Soap bars - 0.05%
 

ngian

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I'm excited to hear your thoughts on your experiment, too. You used much more SC than I do in my soaps. I use 2.6% ppo, which is the equivalent of 2% of citric acid. (I do 2% in my CA batches.) When I made my EDTA batch, I only used 0.5%, like you did.

This is where I got my amounts, if you are wondering. I don't know if you have seen this before (it's from a post by DeeAnna). I made a screen shot of this and literally take it where ever I go. (It's on my phone and saved to my cloud.)

BTW: The colors for the EDTA and SC soaps are beautiful. What did you use to get them?
Hello Teresa

I have also as a reference DeeAnna's notes but straight from her site (which are updated from time to time): http://classicbells.com/soap/citricAcid.html

She notes that: "Typical dosage for sodium citrate is 13 g to 39 g sodium citrate powder for every 1,000 g oils (1.3% to 3.9% ppo). Use more for hard water, less for soft", and as I have very hard water I use the top end range.

I have used many times 4% SC but I was also using salt at 2-3%, and now that I'm using only SC it seems that it makes a softer soap initially.

I colored EDTA with 25 drops of orange pigment in 400gr oils and SC with 25 drops of green pigment in 400gr oils.
 
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ngian

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Hello everyone. I finally found some time to test the specific soap bars while I also got feedback from another soaper too.

We both agree that the white soap that has no "binding metal ions" additives has suds that somehow feel more "heavy" on the touch. It is like when the soap has more lye discount, and that must be for the fact that lime soap (soap scum) behaves somehow like fatty acids, ingredients that are hating water.

On the other hand the other two had "lighter feeling" suds, and as others have described (IrishLass or Teresa), the skin is feeling a little bit more cleaned and lighter. They can also create a few bigger bubbles.

In the EDTA soap with only 0.5% of oils weight this effect is slightly more intense than the CA 4% of oils weight soap bar, So if someone wants to use more biodegradable ingredients, he can use CA instead of EDTA with the similar effect.

Nikos
 

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