EDTA Detractors?

[lenarenee]

I think I agree with the above, but my only concern is that EDTA is a nondegradable ingredient and will remain as is in nature by the end of its mission in soap.

Can you point me to the info where you found this?

I'm considering adding EDTA to my soap, since I'm moving from commercial to possibly 100% use of organic lard/tallow only. Commercial lard has BHT and sometimes citric acid, the organic (Fannie and Flo: my heroes!) has no additives.

I'm wondering how well organic lard soap will fare; does organic fat mean fewer contaminant that will contribute to dos? Or, do the additives in commercial lard prevent dos in soap, not just the fat?

Unfortunately it will be another 18 months or so before I can begin to answer that question while I observe rate of dos in curing soaps.

 

[topofmurrayhill]

I think I agree with the above, but my only concern is that EDTA is a nondegradable ingredient and will remain as is in nature by the end of its mission in soap.

Good point. While the contribution from artisanal soap is minor, apparently you are right. It does degrade more slowly than one would like. Maybe it would be better to use it for stabilization rather than hard water performance, as the usage rate is about 80% lower.

 

[lenarenee]

Good point. While the contribution from artisanal soap is minor, apparently you are right. It does degrade more slowly than one would like. Maybe it would be better to use it for stabilization rather than hard water performance, as the usage rate is about 80% lower.

When you say stabilization you mean preventing rancidity? What would the usage rate be for that?

 

[topofmurrayhill]

When you say stabilization you mean preventing rancidity? What would the usage rate be for that?

Yes. In commercial cosmetic and personal care products I think the usage rate ranges from 0.05% to 0.5% by product weight. For preventing DOS it seems the lower end of the range is sufficient. You could use 0.1% by product weight or even just oil weight.

People on the board who use it to reduce scum and improve lather with hard water have been recommending 0.5% by product weight. That's at the high end but probably necessary for the purpose.

 

[lenarenee]

Thank you for that info TOMH!

 

[penelopejane]

I love it when people experiment and compare the EDTA and citric acid and try salt as well. Great to get different opinions. It's too early for me to see the Citric Acid difference yet

 

[The Efficacious Gentleman]

So 0.1% edta plus 2-3% sodium citrate is a good mix?

 

[topofmurrayhill]

So 0.1% edta plus 2-3% sodium citrate is a good mix?

Actually not, because they are both for the same purpose. Your stabilizer system would best include a chelator (one of the above) to inactivate metal ions, plus an antioxidant.

As far as antioxidants go, our best information right now is that ROE works well with EDTA and BHT works well with sodium citrate.

What might be frustrating is that each of those pairings includes a synthetic product that some people are reluctant to have on their label. My preference is the ROE/EDTA combo. Rosemary oleoresin extract sounds good, plus people aren't quite as well trained to be suspicious of EDTA as they are of BHT. EDTA is also very efficient by weight.

 

[penelopejane]

Actually not, because they are both for the same purpose. Your stabilizer system would best include a chelator (one of the above) to inactivate metal ions, plus an antioxidant.

As far as antioxidants go, our best information right now is that ROE works well with EDTA and BHT works well with sodium citrate.

Does ROE with citric acid react in a bad way?
Why don't they work together?
What if I used salt as well as ROE and CA?

 

[topofmurrayhill]

Does ROE with citric acid react in a bad way?
Why don't they work together?
What if I used salt as well as ROE and CA?

I'm not aware that they react with each other, but I suppose it could be.. Some combinations were tested and that one didn't work as well as either of the two stabilizers used alone. We don't know why. Generally speaking, a chelator and an antioxidant work synergistically, but not every combination.

I'm not aware of salt messing anything up, but not every possible recipe has been tested. It probably doesn't do any harm.

 

[penelopejane]

I'm not aware that they react with each other, but I suppose it could be.. Some combinations were tested and that one didn't work as well as either of the two stabilizers used alone. We don't know why. Generally speaking, a chelator and an antioxidant work synergistically, but not every combination.

I'm not aware of salt messing anything up, but not every possible recipe has been tested. It probably doesn't do any harm.

Thanks. I add the ROE to most oils when I get them. I am testing CA. I use salt. Thank you for the insights. I'll keep experimenting and try to get as close as I can without the other additives. You've been very helpful, as usual.

 

[TeresaT]

Yes. In commercial cosmetic and personal care products I think the usage rate ranges from 0.05% to 0.5% by product weight. For preventing DOS it seems the lower end of the range is sufficient. You could use 0.1% by product weight or even just oil weight.

People on the board who use it to reduce scum and improve lather with hard water have been recommending 0.5% by product weight. That's at the high end but probably necessary for the purpose.

What happens if you accidentally use 5% instead of .5% in your soap? I usually figure out my sugar and salt amount by multiplying .20 by the weight of oils. I was multi tasking (OK, not paying attention!) and instead of entering 1000 x .5 % on my calculator I entered 1000 x .05 = on the calculator. That equal sign makes a huge difference compared to that percentage sign (especially when you forget the period in front of the 5). Anyway, I made a 5# batch of soap and only now realized I added 5% EDTA to it instead of .5% ETDA. Huge difference. Mega difference.

Note to self, don't soap when preoccupied. Second note to self, if something seems weird, it really is: do the math again.

ETA: I should probably quit soaping for a couple of months.

 

[lenarenee]

I have no idea what happens - that is a big difference. You may be able to tell us when you try a sample.

 

[topofmurrayhill]

What happens if you accidentally use 5% instead of .5% in your soap? I usually figure out my sugar and salt amount by multiplying .20 by the weight of oils. I was multi tasking (OK, not paying attention!) and instead of entering 1000 x .5 % on my calculator I entered 1000 x .05 = on the calculator. That equal sign makes a huge difference compared to that percentage sign (especially when you forget the period in front of the 5). Anyway, I made a 5# batch of soap and only now realized I added 5% EDTA to it instead of .5% ETDA. Huge difference. Mega difference.

Note to self, don't soap when preoccupied. Second note to self, if something seems weird, it really is: do the math again.

ETA: I should probably quit soaping for a couple of months.

It won't do any harm to you, but I don't know what it will do to the soap. I haven't tried a high amount, but I think someone here has done it (maybe IrishLass?) but I don't remember exactly what the effect was. Something with the texture maybe. I remember it as something a little negative but not a disaster. Let us know what you notice.

 

[Scooter]

Now I feel like I have been making naked soap... none of my batches have had SC or BHT or EDTA or ROE in them. My oldest batches are over 5 months old now and none have developed DOS.

I would like to know from Penelope and some of you others what the frequency of DOS development is in your own soap-making practice. Do the SC folks actually experience more DOS than the EDTA people IRL? I understand from what I have been reading that DOS occurs more often in soaps where "soft" oils (e.g., olive oil) are more dominant.

Also, what did soap boilers use to prevent DOS hundreds of years before EDTA/BHT/etc were invented?

Scooter

 

[topofmurrayhill]

Also, what did soap boilers use to prevent DOS hundreds of years before EDTA/BHT/etc were invented?

That's a cool question. I'm not sure how far back the knowledge goes, but they knew to use soft water, including distilled water. I don't recall ever seeing a reference to using any additive. Certain soaps where known for turning yellow. The fully boiled process itself removed some things that would catalyze rancidity, and it would have to since they often used raw materials of questionable quality. They also knew that hot process and cold process soap making required using oils of the highest quality, as we do today.

 

[Scooter]

That's a cool question. I'm not sure how far back the knowledge goes, but they knew to use soft water, including distilled water. I don't recall ever seeing a reference to using any additive. Certain soaps where known for turning yellow. The fully boiled process itself removed some things that would catalyze rancidity, and it would have to since they often used raw materials of questionable quality. They also knew that hot process and cold process soap making required using oils of the highest quality, as we do today.

Thanks TOMH! I'm also wondering if salting out glycerin and low/no SF had anything to do with it. I SF between 2 and 3 percent and think my soaps are pretty lush.

Scooter

 

[DeeAnna]

Teresa, I have used 1% and 3% EDTA in a batch of soap. The mixture of EDTA with NaOH solution turns into a thick pasty gravy-like stuff that's worse the more EDTA you use. It's not obvious if you put the EDTA solution into the fats instead and then add the lye, but that's probably just disguising the problem rather than preventing it. In any case, the finished soap with higher EDTA seems okay as far as I can tell. I've since went back to 0.5% since I don't see the higher rates doing any more than the 0.5% as far as reducing soap scum. And certainly you could use much less if you only want to guard against rancidity.

Soapmakers in the 1800s and early 1900s were generally of the opinion that superfat made the soap more liable to rancidity. They preferred the boiled method of soapmaking for that reason, because one can positively ensure there is no superfat in the soap with the boiled method, unlike the cold process method. I have to say, unlike hobby soap makers like us, these fellows probably had the experience to know what they were talking about. In addition to minimizing superfat, some older manuals suggested making no more soap than could be sold reasonably quickly, not only for economic reasons but also because some types of soap deteriorated in storage due to rancidity, shrinkage and warpage due to high water content, and the effects of some of the fillers used in the cheaper types of soap.

Before about 1920, as far as I can tell, soapmakers did not have effective chelators or antioxidants to use. Modern commercial soaps also have a low superfat, but they also often contain chelators and sometimes antioxidants.

 

[penelopejane]

Now I feel like I have been making naked soap... none of my batches have had SC or BHT or EDTA or ROE in them. My oldest batches are over 5 months old now and none have developed DOS.

I would like to know from Penelope and some of you others what the frequency of DOS development is in your own soap-making practice. Do the SC folks actually experience more DOS than the EDTA people IRL? I understand from what I have been reading that DOS occurs more often in soaps where "soft" oils (e.g., olive oil) are more dominant.

Also, what did soap boilers use to prevent DOS hundreds of years before EDTA/BHT/etc were invented?

Scooter

Hi Scooter,
I don't use any of those additives except ROE in some oils. I use salt to harden my soap and Citric Acid to prevent soap scum. I am working with vinegar atm. Will be months before I have any results.

I have never had DOS, touch wood. I am very particular about my soaping hygiene and handle curing soap with gloves or just washed hands always, until it is packaged. I also have a good aeration around my curing racks. My castile is stored in cardboard boxes when it is 6 - 9 months old and I check it regularly.

 

[TeresaT]

It won't do any harm to you, but I don't know what it will do to the soap. I haven't tried a high amount, but I think someone here has done it (maybe IrishLass?) but I don't remember exactly what the effect was. Something with the texture maybe. I remember it as something a little negative but not a disaster. Let us know what you notice.

Teresa, I have used 1% and 3% EDTA in a batch of soap. The mixture of EDTA with NaOH solution turns into a thick pasty gravy-like stuff that's worse the more EDTA you use. It's not obvious if you put the EDTA solution into the fats instead and then add the lye, but that's probably just disguising the problem rather than preventing it. In any case, the finished soap with higher EDTA seems okay as far as I can tell. I've since went back to 0.5% since I don't see the higher rates doing any more than the 0.5% as far as reducing soap scum. And certainly you could use much less if you only want to guard against rancidity.

Soapmakers in the 1800s and early 1900s were generally of the opinion that superfat made the soap more liable to rancidity. They preferred the boiled method of soapmaking for that reason, because one can positively ensure there is no superfat in the soap with the boiled method, unlike the cold process method. I have to say, unlike hobby soap makers like us, these fellows probably had the experience to know what they were talking about. In addition to minimizing superfat, some older manuals suggested making no more soap than could be sold reasonably quickly, not only for economic reasons but also because some types of soap deteriorated in storage due to rancidity, shrinkage and warpage due to high water content, and the effects of some of the fillers used in the cheaper types of soap.

Before about 1920, as far as I can tell, soapmakers did not have effective chelators or antioxidants to use. Modern commercial soaps also have a low superfat, but they also often contain chelators and sometimes antioxidants.

Thanks for the info. I was wondering if the soap would be mushy and non-sudsing. I tried one of the bars today and was not impressed. It's probably the worst feeling soap I've made so far. I'll give it some more time to check it again.

I made it last week for the Home Sweet Home swap and realized my error today. I guess I'm going to drop out of the swap. This is the second major error dealing with that swap. I think the powers that be are trying to tell me something...