# De-ionised water & EDTA questions



## Sonya-m (Jun 10, 2015)

Is de-ionised the same as distilled? 

I'm sure I read the usage rate for EDTA is 0.5% total oil weight but can someone confirm? I remember you can make a 39% solution in advance but it's the end quantity I can't remember


----------



## DeeAnna (Jun 10, 2015)

The EDTA dosage can range from 0.2% to 4% of EDTA powder. The amount depends on what you want to do. Use 0.2% to 0.5% to chelate metal ions for longer shelf life (aka less chance of DOS). Use 0.5% to 4% to reduce hard water scum. 

Most people on SMF use 0.5% of EDTA powder based on total fat weight, especially if they're adding EDTA to bar (NaOH) soap. This seems to work pretty well and is pretty much the soapers' usual way of figuring additives. Others (Irish Lass) base their dosage on the total batch weight. This method is easy to use when adding EDTA to diluted liquid soap AND this method more closely follows the manufacturer's recommendations, so you could use it for bar soap as well.

Even though you get different answers with the two methods, EDTA seems to be effective despite this variation in dosage. If you use total fat weight to calcuate the EDTA and you're not getting the results you want at 0.5%, try increasing the percentage a bit -- say 0.75% or 1% -- but don't go overboard. I can speak from experience that even higher rates of EDTA (3-4%) can be troublesome to use in CP soap and I really don't see a benefit to the higher amounts, so I suggest sticking with a lower dosage however you want to calculate it.

Irish Lass recommends dissolving EDTA in water to make a 39% solution by weight. This would be a mixture of 39 grams of EDTA powder with enough warm distilled water added to make a total of 100 grams of solution. 

Be sure to use TETRAsodium EDTA, not DIsodium EDTA. TETRA is for alkaline products like soap and DI is for neutral to acidic products.

Here's how I calculate how much 39% solution to add, based on total batch weight:
Weight of 39% EDTA solution = (% EDTA powder in the soap) X (Total batch weight) / 39

Example 1: The total batch weight is 1000 grams and I want 0.5% EDTA in the recipe. The weight of EDTA solution is:
Weight 39% EDTA solution = (0.5) X (1000 grams) / 39 = 12.8 grams

Example 2: The total batch weight is 16 ounces and I want 0.5% EDTA in the recipe. The weight of EDTA solution is:
Weight 39% EDTA solution = (0.5) X (16 ounces) / 39 = 0.21 ounces

Irish Lass explains the math differently, but she and I end up in the exact same place.

Note: The Lotioncrafter EDTA powder I'm using is 83% to 85% pure. If you're using EDTA powder with a greatly different purity, you might want to take that into account. Just a few percent difference is not a big deal, however -- just use the same formulas that Irish Lass or I are using.


----------



## DeeAnna (Jun 10, 2015)

Oh, forgot ... deionized is technically not the same as distilled, but good quality deionized water approaches the quality of distilled. I know distilled can be ridiculously expensive in some places, so I'd certainly used deionized if it was easier to get and/or cheaper than distilled.


----------



## IrishLass (Jun 10, 2015)

Yep- like DeeAnna said, I like to work from a 39% solution of tetrasodium EDTA. I like to use it at .5% of my total batch weight, including the weight of my water and lye and all my additives, etc. I don't know what % that works out to be if based on just the oils, but for what it's worth, .5% of my entire batch weight is plenty enough EDTA to increase my lather in my hard water and to also cut down on scum. It hasn't cut the scum out completely, but it has definitely put a dent in it, and when I use my soap in the shower, it almost feels like I'm washing with soft water in the way the soap rinses off my skin. It's really nice- plus it has the added benefit of keeping DOS at bay.

Also- like DeeAnna explained, I do my math differently to figure out how much 39% tetrasodium EDTA to add to my batch (I learned it from someone over at the Dish and it's what I've gotten used to). For what it's worth, here is the 2-part equation that I do: 

1) The total weight of my soap batch (in grams) X .5% = how much powdered EDTA is required for my batch.
2) The amount of powdered EDTA required for my batch X 2.56 = how much of my 39% solution to weigh out for my batch.


IrishLass


----------



## Sonya-m (Jun 10, 2015)

This is why I love this place!! Thank you both for such informative answers!!

So after running my recipe through soapcalc if, for example, my total weight of everything came to 1000g I would use just 5g EDTA?

This is the one I have, do I need to be concerned it states 86% in the title? Should I increase to 5.8g to account for it?


----------



## DeeAnna (Jun 10, 2015)

"...I like to use it at .5% of my total batch weight, including the weight of my water and lye and all my additives, etc...."

Yes, Irish Lass, I agree -- now that I've finally got my head in the game and am thinking about this correctly. This method follows the supplier's instructions. 

I think some people use the % based on fat weight when they are calculating EDTA for use in bar (NaOH) soap because that seems to be a traditional soapers' way of doing things. This would give a lighter dose of EDTA compared with basing it on total batch weight. That means you might need to use a slightly higher % of EDTA based on fat weight to get the same results as if you based on the total batch weight. I'd still start at 0.5% of total fat weight and see how that works -- it might be fine.

"...my total weight of everything came to 1000g I would use just 5g EDTA?..."

Yep, that's right.

"...do I need to be concerned it states 86% in the title?..." 

Um, in what title? Could you please clarify?


----------



## Sonya-m (Jun 11, 2015)

Oops I didn't add the link to the one I got!!

http://m.ebay.co.uk/itm/261820309045?nav=SEARCH


----------



## DeeAnna (Jun 11, 2015)

Okay, I understand you now. Thanks!

I've been using EDTA from Lotioncrafter. I went back and read through the info more carefully, and I now have egg on my face. The EDTA I'm using is 83% to 85% pure, pretty much the same as yours. The balance is water. I doublechecked the usage rates and they are meant for the actual product as sold (~85% pure), so the advice given in earlier posts in this thread is correct for your EDTA as well as mine.

Short answer -- Yes, stick with the 5 g of EDTA per 1000 g total weight, Sonya. You don't need to adjust for the purity.


----------



## DeeAnna (Jun 11, 2015)

I've revised my answers in posts 2 and 6 -- please re-read. I needed to correct some of the things I originally wrote. My head's definitely not in the game -- I'm sorry for the confusion....


----------



## Saponista (Jun 12, 2015)

In my experience, edta will only go into solution at a pH if 8 or over. If you try to dissolve it in water you will just end up with a precipitate. I have seen many newbie lab techs try to make this without success. As soon as you start adding some naoh to bring the pH up it starts to dissolve. So if you want to make a solution before hand, it's going to have to be a slightly alkaline one.


----------



## Sonya-m (Jun 12, 2015)

I didn't have time to make a solution last night so just added it to my water before my lye, seemed to be ok


----------



## Saponista (Jun 12, 2015)

Perhaps it will dissolve at the lower pH in the small quantities you are using.


----------



## DeeAnna (Jun 12, 2015)

Saponista, I have to say I had zero problems making solutions of tetrasodium EDTA and warmed distilled water. The EDTA powder dissolved quickly and easily and has remained fully in solution since then. I made about 220 grams of solution each time, so, yes, it was only a small amount. If I do have trouble in the future, however, I'll keep your tip in mind.


----------



## Saponista (Jun 12, 2015)

Ok perhaps it is only when you are making the higher molarity solutions.


----------



## DeeAnna (Jun 12, 2015)

I didn't find any solubility tables in a quick search of the 'net, but I did find this info from Sigma Aldrich:

*Tetra*sodium EDTA: This product is soluble in water at room temperature up
to 1.45 M, which is ~550 mg in a final volume of 1 ml.
The pH of this solution will be 10 to 11 and will be
rather viscous. EDTA salts are more soluble in water as
the pH increases: the more EDTA there is in the salt
form, the higher the pH of a water solution, and
therefore, the higher the room temperature solubility
A stock solution of 0.5 M at pH 8.5 may be stored for
months at 4 °C without degradation.1

*Di*sodium EDTA: This product is slowly soluble in water at room
temperature up to 0.26 M, which is approximately
96 mg in a final volume of 1 ml. The pH of this
solution will be in the range of 4 to 6. EDTA salts are
more soluble in water as the pH increases: the more
EDTA there is in the salt form, the higher the pH of a
water solution, and therefore, the higher the room
temperature solubility. This can be achieved by a
gradual addition of concentrated sodium hydroxide
solution to the EDTA solution. A stock solution of 0.5 M at 
pH 8.5 is stable for months at 4 °C.

From this info, it looks like Tetra EDTA is quite a bit more soluble in water than Di. At a 39% w/w solution of Tetra and water per Irish Lass, we're making about a 1 M solution, if I'm doing the math correctly, so the molarity is fairly high although the solution is well below saturation. 

On the other hand, this info shows Di EDTA is tough to dissolve and has a low saturation concentration in plain water. If you're using Di ETDA rather than Tetra, I can see why your experience and ours might be quite different!


----------



## Saponista (Jun 12, 2015)

It must be the disodium that I am thinking of then.


----------



## not_ally (Jun 12, 2015)

Definitely the di, Saponista, I make up 16 oz. squeeze bottles of the tri at 39% (thanks IL and DeeAnna) and use it all my batches, it dissolves pretty easily and stays suspended.  Thank goodness, I need it for the chelation.


----------



## topofmurrayhill (Jun 12, 2015)

Aren't those usage rate suggestions from Lotioncrafter a little (very) high? The Dunn experiments used 0.1% for stabilization. Dow Chemical suggests 0.1% to 0.2% for bar soaps. Those rates seem more typical.


----------



## hozhed (Jun 13, 2015)

DeeAnna said:


> The EDTA dosage can range from 0.2% to 4% of EDTA powder. The amount depends on what you want to do. Use 0.2% to 0.5% to chelate metal ions for longer shelf life (aka less chance of DOS). Use 0.5% to 4% to reduce hard water scum.
> 
> Most people on SMF use 0.5% of EDTA powder based on total fat weight, especially if they're adding EDTA to bar (NaOH) soap. This seems to work pretty well and is pretty much the soapers' usual way of figuring additives. Others (Irish Lass) base their dosage on the total batch weight. This method is easy to use when adding EDTA to diluted liquid soap AND this method more closely follows the manufacturer's recommendations, so you could use it for bar soap as well.
> 
> ...


 
DeeAnna......why use a chelant for soap if you use distilled water? Where are the metals coming from?  thanks


----------



## Sonya-m (Jun 13, 2015)

They're coming from the water you bathe/shower in.


----------



## hozhed (Jun 13, 2015)

Sonya-m said:


> They're coming from the water you bathe/shower in.


 
Sonya,....you mean the metals affect the soap at the point of use?  In what way?


----------



## not_ally (Jun 13, 2015)

Hoz, those of us who have hard water - that with lots of chemicals/metal - coming out of the tap end up with lots of soap scum when we use our handmade soap, the oils (I think) combine with the chemical stuff and create scum which, while not dangerous or otherwise unhealthy, is ugly and messy.   Commercial soaps include lots of chemicals to deal with that, I guess it would be hard to sell them otherwise, ours don't typically.

I think some oils are worse for that, including (eg and unfortunately) lard, which I love and use in large proportions.  Chelators, EDTA is the best, help with that by binding to the scum and carrying it down the drain instead of having it stick to the tub or you when you are bathing.  I'm sure DeeAnna can give you a better explanation, but that's the layman's version!


----------



## hozhed (Jun 13, 2015)

not_ally said:


> Hoz, those of us who have hard water - that with lots of chemicals/metal - coming out of the tap end up with lots of soap scum when we use our handmade soap, the oils (I think) combine with the chemical stuff and create scum which, while not dangerous or otherwise unhealthy, is ugly and messy. Commercial soaps include lots of chemicals to deal with that, I guess it would be hard to sell them otherwise, ours don't typically.
> 
> I think some oils are worse for that, including (eg and unfortunately) lard, which I love and use in large proportions. Chelators, EDTA is the best, help with that by binding to the scum and carrying it down the drain instead of having it stick to the tub or you when you are bathing. I'm sure DeeAnna can give you a better explanation, but that's the layman's version!


 

Ok, that makes sense. I wonder if that's why some here make "salt bars"?  We use EDTA and other chelants where I work to tie up metals because they inhibit the bleaching process which is not good. I wonder if I can get a deal on EDTA ,since we buy it by the train car load???


----------



## not_ally (Jun 13, 2015)

I've never considered salt as something which might help with chelation, is there some kind of chemistry there that would lead to that?  As you can probably tell, I am not good at that stuff, although I find it interesting and try hard to understand.

EDTA is not super cheap, I think it is about $15 for a lb on ebay, but it goes a pretty long way for me since I am a hobbyist.  I haven't really worked out the cost ppo or anything, just mix it up in those 16 oz squeezies, so don't have to mix it that often, but it's not comparable to using really expensive stuff like FOs.  I bet you could get it cheaper through work, though.


----------



## DeeAnna (Jun 13, 2015)

"...why use a chelant for soap if you use distilled water? Where are the metals coming from?..."

What the others are saying is all spot-on, Hozhed. 

Metal ions such as copper (Ca++) can cause DOS/rancidity in a finished soap bar. These metal ions are catalysts for rancidity, in that they greatly increase the speed of the chemical reactions that cause fat to go rancid. 

One way to minimize these metal contaminants is to avoid using ingredients that contain them. For example, I use distilled water to make my soap because it has zero or only a trace of metallic impurities. Tap/drinking/spring water may or may not contain metals that trigger DOS, which is why some people have problems using tap water in soap and others don't. You can't tell if there are metallic impurities in tap water unless you test for them. 

But other ingredients, including most soaping fats, normally contain some metallic impurities, so a soaper can only do so much to avoid this problem. It's good to have a backup plan, and one way to deal with metals that sneak their way into finished soap is to use a chelator such as EDTA. A chelator has chemical "claws" that can latch onto and immobilize certain types of ions. You need only trace amounts of EDTA for this purpose -- just enough to bind up those pesky trace metals lurking within the soap bar.

Another issue that chelators can help with is to bind up the metals in your tap water that react with soap to make hard water scum when you're using the soap in the bath or shower. This scum feels icky on the skin, and it reduces the lather of the soap -- if the soap is being forced to create scum, it can't make nice suds! Metal ions like calcium and magnesium are the culprits here. 

Softening the water helps a lot because typical home water softeners replacing calcium and magnesium ions with sodium ions that don't cause trouble. If you don't have soft water, then adding a chelator like EDTA to your soap can help reduce hard water scum. A higher dose of EDTA is going to be better for this purpose because the EDTA has to to chelate the metal ions in the water that's mixing with the soap on your washcloth. A chelator in your soap might not reduce soap scum entirely, especially if your water is super hard, but it will certainly help.

On a related note, there's more about this here: http://www.soapmakingforum.com/showthread.php?p=509320 Jump to post 39 to skip to the EDTA part of this thread.


----------



## hozhed (Jun 13, 2015)

DeeAnna said:


> "...why use a chelant for soap if you use distilled water? Where are the metals coming from?..."
> 
> What the others are saying is all spot-on, Hozhed.
> 
> ...


 
Excellent DeeAnna, thank you and the rest for the input.

As an aside, chelants are for sure, very effective. I am a papermaker, and we use around 4lb. chelant  per TON of wood pulp to tie up metals that inhibit bleaching. Pretty efficient.


----------



## DeeAnna (Jun 13, 2015)

Salt (table salt, NaCl) cannot act as a chelator -- it just doesn't have the chemical structure to do that kind of job -- so people make salt bars for reasons other than expecting the salt to deal with hard water scum.


----------



## not_ally (Jun 13, 2015)

Thanks, DeeAnna, you save me from yet another chelation experiment.  I am on a lifetime quest to defeat the evil scum, at least as much as possible.


----------



## rosche (Jul 9, 2015)

Hello everyone.  I have the same question as topopfmurrayhill.  I see somewhere that Dunn sugesst 0.1% of edta.  But it's also combine with 0.1% sodium citrate and BHT. 

I hope I'm not OOT but what does the combination of edta and sodium citrate do in soap? Is it better to use both? Or edta only is enough (as chelating agent and water softener and lather booster)

I also read somewhere that edta can be an emulsifier too. Is it true?


----------



## DeeAnna (Jul 9, 2015)

Kevin Dunn evaluated chelators specifically for reducing rancidity in bar soap, not for reducing soap scum when the soap is being used for bathing. If all you want to do is protect against rancidity/DOS, by all means follow Dunn's recommendations for the dosages of the various chelators and anti-oxidants. Otherwise, kindly re-read the last half of my Post 25 (above), specifically the next to last paragraph.

"...Dunn sugesst 0.1% of edta. But it's also combine with 0.1% sodium citrate and BHT...."

Nooooo .... I am quite sure that is not what Dunn said, at least in his Scientific Soapmaking book. In the book, Dunn only looked at pairing one chelator and one anti-oxidant. And it was EDTA at 0.5%, not 0.1%. Re-check your source?

"...I also read somewhere that edta can be an emulsifier too. Is it true? ..."

Not that I am aware of, and a quick Google search did not bring anything up about this. If you would like a better answer, please provide the source so I have something more to go on.


----------



## not_ally (Jul 9, 2015)

Rosche, the link that DeeAnna posted in #25 is really helpful.  Somewhere it it, TOMH provided a link to the Dunn chapter on this stuff, it is this:  http://cavemanchemistry.com/DreadedOrangeSpot-Dunn.pdf

As DeeAnna says, it refers specifically to DOS, but is pretty helpful in that respect.

D, I have another EDTA question for you - aren't you sick and tired of them ?  I have been using one of my brine bars regularly at the bathroom sink.  The formula is 65% lard, 15% CO, 13% olive, 7% castor, salt as 25% of the water weight.  Also .5% EDTA, 3% sodium lactate and the equivalent of 1.5 TB sugar, ie, in a 50/50 sugar solution.  All in a batch of 24 oz oils.

So, adding EDTA has been wonderful in terms of dealing with the scum, generally, I have hardly been noticing it these days. It is particularly evident in the sink b/c I use it so often there and the non-EDTA soapies made a big mess. But the scum rings have reappeared, if less badly, with the brine soap.  Is it b/c of the extra NaCL, do you think?  If so, would upping the EDTA help?  

I have just made several batches of salt soap, am wondering if I should be upping the EDTA in those, espec. b/c the salt amts are higher than in brine (80%, 50% and 30% of oils - not water - respectively.)


----------



## rosche (Jul 9, 2015)

THank you so much for the answer DeeAnna and not_ally. I should learn more >_<


----------



## not_ally (Jul 9, 2015)

This place is a good one to start!  There is so much information and help ....


----------



## DeeAnna (Jul 9, 2015)

Not_ally -- I don't have a good answer for you. You either have soap scum forming, or you have excess soap or superfat being deposited rather than dissolving in your water. Try an experiment -- If you have a patch of goo on your shower or sink to mess with, let a few drops of your EDTA solution soak on some of the goo for a few minutes. Rinse gently with cold water. The EDTA should dissolve the goo if it really is soap scum. If that is the case, then a higher dose of EDTA might be good to try.


----------



## not_ally (Jul 9, 2015)

What a great idea, D.  Thank you! Will do so and report back later.  Sometimes I feel guilty pestering you so much, let me know via PM if you want a break ...


----------



## Lion Of Judah (Jul 16, 2015)

are there any alternatives to EDTA ?


----------



## DeeAnna (Jul 16, 2015)

Sodium citrate is also a chelator, Lion.


----------



## Lion Of Judah (Jul 17, 2015)

"Much thanks for the reply DeeAnna" , i was looking up the other day about EDTA and found some info that made me want to seek out an alternative.
...."*Tetrasodium EDTA* is a preservative that’s made from the known carcinogen, formaldehyde and sodium cyanide. (see how)  It is also a penetration enhancer, meaning it breaks down the skin's  protective barrier, going right into your bloodstream. Many companies  trying to be "natural" will use Tetrasodium EDTA instead of parabens to  preserve their products. In my opinion, Tetrasodium EDTA is just as bad."

so i'm glad that there is a alternative . [ citric acid same thing ?]


----------



## DeeAnna (Jul 17, 2015)

I don't expect to change your thinking on this matter, but I must respectfully point out that your source of information is a poor one. 

***

"... It is also a penetration enhancer, meaning it breaks down the skin's protective barrier, going right into your bloodstream...."

I'd say this study provides more useful and even handed information about the "horrors" of EDTA being a skin penetration enhancer. 

Do keep in mind that I'm an engineer first and foremost, and my bent is to give more weight to peer-reviewed studies than internet bloggers. I have no respect for writers such as the one on bubbleandbee.com who make unsubstantiated statements designed to stir up fear and confusion rather than create understanding and respect.

***

"...Tetrasodium EDTA is a preservative that’s made from the known carcinogen, formaldehyde and sodium cyanide..."

Yes, the main chemical process to make EDTA uses chemicals that can injure and even kill. As an engineer who used to work in plants that manufactured useful chemicals, I know that's often the way chemistry works -- you sometimes have to use highly reactive and dangerous chemicals to create certain types of chemicals. 

Soap falls in that category too. We use NaOH or KOH -- highly reactive, dangerous chemicals that can quickly injure and even kill -- to make a product that is much more benign and arguably beneficial. Does the character of the lye remain in the soap? No. 

Should we then judge the safety and usefulness of soap by the chemicals from which it's made? Some uninformed and fearful people most certainly do believe that to be true -- just check out the various internet bloggers who assert that soap can be made without lye -- here's one example. And still others, such as this one, who issue a blanket warning of "...Make sure it’s [sodium hydroxide] not in any of your skincare!..." But we as soapmakers know better. We respect the lye when we use it ... and enjoy the soap after the lye has been transformed into that beneficial end product.

So moving on to EDTA, is it then correct to think the formaldehyde and cyanide used to make EDTA remain in the finished EDTA? No. But there are quite a few fear-mongering bloggers who say exactly that to stir up controversy and blind loyalty amongst people who would rather be governed by fear than by facts.

***

"...Many companies trying to be "natural" will use Tetrasodium EDTA instead of parabens to preserve their products...."

EDTA is a chelator, not a microbial preservative. Anyone who takes a small amount of time to learn about proper product formulation will not make the mistake of confusing EDTA as a preservative. This is another unsubstantiated claim intended by the blogger to create fear and confusion, not respect and understanding.

***

Use EDTA if you want to. Or don't. It doesn't matter to me. But the koolaid being served by internet bloggers like this one is not a good basis for rational decision making.


----------



## Sonya-m (Jul 17, 2015)

I think I might love you DeeAnna!! I KNEW you would respond like this, I wanted to but knew you'd do a much better job!


----------



## not_ally (Jul 17, 2015)

I come across blogs setting forth parades of horribles w/r/t/ "non-natural" additives all the time because I am so OCD about research. Not to be mean, but the quality of the writing and the analysis/thought process behind most of the posts and comments is so poor that it is very hard to take them seriously, even in the occasional instance in which they are making good points.   

I just kind of roll my eyes and move on.  We live in a time with lots and lots of options, and lots and lots of information.  I am happy to take the extremely minimal risks associated w/ EDTA, BHT, preservatives and the like in exchange for the very substantial benefits.

ETA:  this is not to diss you or your post, Lion, just prompted by seeing a blog post on preservatives a little while ago.


----------



## cmzaha (Jul 17, 2015)

Is Sodium Citrate as good as EDTA for chelating? I ask the question, even though I am not afraid of EDTA, when a customer reads a label and sees an ingredient they have heard is bad they simply will not buy the product. This is why I hate all the scare mongers on the internet. I actually had a customer ask why I use so many chemicals in my soap, now she bypassed the NaOH and the citric acid and went to the sucrose listed on my label. I had a tough time convincing her sucrose is sugar and used to help create bubbles, it was actually her husband that convinced her it was sugar. I am sure I would have lost the sale if I had EDTA listed.


----------



## DeeAnna (Jul 17, 2015)

I haven't done the testing and research to know, Carolyn. Something someone else mentioned recently in another SMF thread made me wonder if citrate is somewhat less effective in controlling soap scum, but I can't speak with any authority about that. 

Citrate in soap is arguably more "crunchy" than EDTA, so I can see why a soap maker might use citrate if only for greater customer acceptance. I suppose some customers, like the lady who was suspicious of sucrose, might have problems with citrate too, regardless of its benefits.


----------



## cmzaha (Jul 17, 2015)

DeeAnna said:


> I haven't done the testing and research to know, Carolyn. Something someone else mentioned recently in another SMF thread made me wonder if citrate is somewhat less effective in controlling soap scum, but I can't speak with any authority about that.
> 
> Citrate in soap is arguably more "crunchy" than EDTA, so I can see why a soap maker might use citrate if only for greater customer acceptance. I suppose some customers, like the lady who was suspicious of sucrose, might have problems with citrate too, regardless of its benefits.


Thankyou DeeAnna. What you say about the "citrate" is true but I list what goes into the soap, so I list it as citric acid :grin:
I now sell in a large Asian population and believe me when I say they read every label on every soap they pick up. I think I will get in some EDTA so I can compare. I do know I still get some scum in the shower, but not as much as before I used the citric + extra lye


----------



## Lion Of Judah (Jul 17, 2015)

Thank you DeeAnna for the breakdown of info , 1st. it's the reason why I personally seek you out for the straight dope on things. i do not use many of the additives out there in my soap and the target group that i plan to sell to [when i get around to it / "confident enough" ] fall into the sector that will read ingredients label and scrutinize what goes into the soap. 2nd i personally always seek out alternatives in case there is something more readily available at my disposal. 
not_ally do not worry about me taking any of it as a "dis" , you all are my peers and sounding board , and more info garnered affords me the opportunity to make better choices based on info given and my comfort level. I'm striving to get a product that i like and sure a customer will love.
i still make soap the same way i learned it , plus the improvements i have made in consistency and quality. i still to this day check temperature and am a minimalist when it comes to colorants such as botanicals  and herbs. and have not gotten comfortable about oxides - mica and the rest as of yet but so it go.
so in parting the "straight dope" is what i relish , i may not know all the chemistry of things but straight talk i understand  its how i learn . [ Dee , a triple dose of thanks your way always]


----------



## DeeAnna (Jul 17, 2015)

Awww. Thanks, Lion. I appreciate your straight talk too!!!! I have been worried I might have offended you by my reply. I tried to make my words as neutral as I could manage, but I'm sure it's obvious I have strong opinions and it isn't easy to write in a neutral, objective tone when I feel that way. Thanks for understanding!

I get your point about having a minimalist approach. I generally avoid using additives unless I think there's a good reason for using them. My interest in EDTA and citrate came from getting occasional spots of DOS on my soap. In looking at the problem, these isolated spots appear to be triggered by flecks of impurities -- perhaps bits of metals or whatever. 

I wanted to reduce the chance of this happening, and in my studies I came across Kevin Dunn's experiments with chelators and antioxidants to reduce the color change in soap (color change being an indicator of potential DOS). I then learned about the role EDTA and citrate can play in reducing soap scum when soap is used with hard water. And so ... ta-da ... two benefits with one chemical. I'm still learning about all this, however, so I reserve the right to change my mind about these additives.  So far, I do think they offer some benefits if used carefully.

ETA: I don't know of anything else that will help with soap scum, but other things I do to prevent DOS include these -- 

minimize exposure of my bar soaps to light -- keep them covered, keep them in a dark cabinet, etc
always keep soap covered to prevent dust from settling on them -- I use old lint-free cotton or linen towels and such
I store soap in cardboard boxes, but the boxes are lined in clean cotton towels so the soap never touches the cardboard
handle soap only with freshly washed hands
if I use water on the soap to do something like washing off soda ash, I only use distilled
minimize the use of metal utensils when soaping -- silicone spatulas are my friend, although my SB is stainless steel
use distilled water as much as possible when making (that's not always possible, but I try)
minimize superfat in my recipes (yeah, I know -- controversial!)
package soap in shrink bags as soon as the soap is cured, again to prevent contamination from dust, dirty fingers, etc.


----------



## jules92207 (Jul 18, 2015)

I have been very interested in this topic for some time now and I too appreciate all the straight talk discussion. Huge kudos to DeeAnna for always making me want to learn more and understand deeper what does what and why. 

Also huge kudos to everyone with good questions and thoughts to help facilitate discussion. I learn more here than anywhere, I tell ya.

I also have Kevin Dunn's book on my amazon wish list now. Thank you!


----------



## Saponista (Jul 20, 2015)

I also love your answers DeeAnna. Thank you for always being so helpful and informative. I wish there were more voices like yours to counteract the sea of misinformed detrimental nonsense that seems to prevail over actual facts. I would like to sell my soap at some point and there are several ingredients that I would like to use but know they will have a negative impact on sales due to internet based negativity. Titanium dioxide being one of them.


----------

