EDTA chelator

[Wendjie]

Allô everyone! I would like to know what do you think about using edta in your cp soap? And what is the minimum to use per pound? Thanks!

 

[earlene]

Not only does it reduce soap scum in my sink, tub & shower, but I use it in combination with Rosemary Oleoresin Extract (ROE) to reduce the likelihood of rancidity (DOS - dreaded orange spots).

Here are a some links with usage rates for both:

The first 2 are really that same article, done as a scientific study by Chemistry professor, Kevin Dunn and his students:

https://www.soapguild.org/how-to/make-soap/dreaded-orange-spot.php
and if you want to save this to your computer in pdf, click this link: http://cavemanchemistry.com/DreadedOrangeSpot-Dunn.pdf

More on chelators from @DeeAnna, the latter also including how to usage rates for EDTA & how to prepare it prior to use:

https://classicbells.com/soap/chelator.asp
https://classicbells.com/soap/EDTA.asp

 

[Wendjie]

Not only does it reduce soap scum in my sink, tub & shower, but I use it in combination with Rosemary Oleoresin Extract (ROE) to reduce the likelihood of rancidity (DOS - dreaded orange spots).

Here are a some links with usage rates for both:

The first 2 are really that same article, done as a scientific study by Chemistry professor, Kevin Dunn and his students:

https://www.soapguild.org/how-to/make-soap/dreaded-orange-spot.php
and if you want to save this to your computer in pdf, click this link: http://cavemanchemistry.com/DreadedOrangeSpot-Dunn.pdf

More on chelators from @DeeAnna, the latter also including how to usage rates for EDTA & how to prepare it prior to use:

https://classicbells.com/soap/chelator.asp
https://classicbells.com/soap/EDTA.asp

Wow thank you i am gonna read this. I beigin to use citric acid but is that mean that edta can replace citric acid for the soap scum or i use both?

 

[ResolvableOwl]

Per the findings of Kevin Dunn (see the PDF that @earlene linked), EDTA is better than citrate at delaying rancidity, in particular when combined with ROE. On the other hand, citrate works just as well with soap scum, might be cheaper/easier to obtain, and is less environmentally worrying. Using both at the same time should be just fine – for more rigorous claims, one would have to conduct tests on a controlled, scientific level.

 

[The Efficacious Gentleman]

I only add citric acid and increase the lye to make sodium citrate, as other things are harder to get hold of here in Austria. I've not had issues with rancidity, so the easily accessible citric acid (baking section of every supermarket!) is the much better option for me

 

[gloopygloop]

I like to use Sodium Gluconate as a chelator, I do have Sodium Citrate and both are available online here in the UK as is Citric Acid, but with the first two you dont have to work out how much extra lye to use, its just add your percentage to the lye water and voila! works well as chelators Sodium Gluconate I feel is the better one IMHO. These will deal with soap scum but I dont think they will deal with DOS/ rancidity, that would need to be ROE I imagine, I have some but almost never use it so cannot advise any findings as to whether it really works or not.

 

[earlene]

As far as using 2 chelators together, there are soapers who do so. In fact, I am planning to give it a try myself at some point soon, perhaps in 2022. I plan to use EDTA + Sodium Gluconate together as a trial.

I have not used citrate or citric acid (to be converted to citrate), mostly because I had already purchased the EDTA and didn't want to do any more math calculations to correct the amount of NaOH needed in the soap formula. But I think the calculations were made easier by a member, galaxyMLP (see this link) but I still haven't tried it because I have so much EDTA on hand. I should try it someday, just so I have the experience, after all I do have citric acid (usually available where canning goods are sold here in the US) and do much canning these days.

 

[gloopygloop]

As far as using 2 chelators together, there are soapers who do so. In fact, I am planning to give it a try myself at some point soon, perhaps in 2022. I plan to use EDTA + Sodium Gluconate together as a trial.

I have not used citrate or citric acid (to be converted to citrate), mostly because I had already purchased the EDTA and didn't want to do any more math calculations to correct the amount of NaOH needed in the soap formula. But I think the calculations were made easier by a member, galaxyMLP (see this link) but I still haven't tried it because I have so much EDTA on hand. I should try it someday, just so I have the experience, after all I do have citric acid (usually available where canning goods are sold here in the US) and do much canning these days.

It would be good to hear your views on performance of Citric Acid and / or Sodium Gluconate as opposed to EDTA, lather /scum/ DOS etc. when you get around to giving them a go.

 

[Wendjie]

I like to use Sodium Gluconate as a chelator, I do have Sodium Citrate and both are available online here in the UK as is Citric Acid, but with the first two you dont have to work out how much extra lye to use, its just add your percentage to the lye water and voila! works well as chelators Sodium Gluconate I feel is the better one IMHO. These will deal with soap scum but I dont think they will deal with DOS/ rancidity, that would need to be ROE I imagine, I have some but almost never use it so cannot advise any findings as to whether it really works or not.

I order EDTA but didnt receive yet. I plan to use both citric acid/EDTA cause i lost about hundred soap trying to find what was wrong and find out it was contaminant, from where??? Still dont know but i am not taking any chance still the citric acid seem to work well. Maybe also add roe to m'y oil when i will open it . Sodium gluconate seem to be expensive here so didnt try.

 

[Peachy Clean Soap]

I won't make a soap w/ out it. I use 'Sodium Gluconate' ROE i just started implementing in large containers of Fats that I want to help prolong shelf-life' then i'll freeze or refrigerate both depending on space & usage.

 

[DeeAnna]

...I plan to use both citric acid/EDTA...

Be careful about combining chelators, because they may interact in unexpected ways and you may not get the results you expect. Don't fall into the trap of assuming "if one is good, then more is better."

Carolyn (cmzaha) uses EDTA and sodium gluconate with good results, but I don't know of anyone who uses a citrate and EDTA combination. I'm not saying it won't work, just that there's not a lot of background to know for sure this combination will be any more effective than one chelator alone.

Why not try one chelator -- EDTA alone works wonderfully in my experience -- and see how that works?

 

[Wendjie]

Be careful about combining chelators, because they may interact in unexpected ways and you may not get the results you expect. Don't fall into the trap of assuming "if one is good, then more is better."

Carolyn (cmzaha) uses EDTA and sodium gluconate with good results, but I don't know of anyone who uses a citrate and EDTA combination. I'm not saying it won't work, just that there's not a lot of background to know for sure this combination will be any more effective than one chelator alone.

Why not try one chelator -- EDTA alone works wonderfully in my experience -- and see how that works?

Yes thats a good advice thank you i will try this!

 

[The Efficacious Gentleman]

And as for the maths, it's actually very simple if you are using the same batch size each time - you'll need a set amount of citric acid and a set amount of lye to react with that each and every time. So you take your calculated lye amount for saponification with the oils and add on the never changing extra lye for the citric acid.

 

[ResolvableOwl]

35 g citric acid (monohydrate) + 20 g NaOH → 43 g trisodium citrate (anhydrous) + 12 g water

7 g citric acid = 8 g masterbatch NaOH 50%