# Is it possible to lower the Ph of cold process soap



## soapqueen (Oct 23, 2009)

Is there anything that can be done to lower the Ph so that the soap is closer to neutral?


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## honor435 (Oct 23, 2009)

i think handmade soap is going to be higher than store bought, what numbers is neutral? i think alot of people on here dont believe in even checking the ph?they do zap test.


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## IrishLass (Oct 23, 2009)

According to all the soapers with a chemistry background, the answer is no. Handmade lye soaps would cease to be soap if the pH were neutral. Chemically speaking, they would separate and become a gooey mess. It's the nature of lye soap to be on the alkaline side, between 9.5 to 10.5. If you want a neutral bar of soap, your best bet is Melt and Pour.

IrishLass


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## Manda (Oct 23, 2009)

I am really interested in finding out more about pH of soap and if there are any methods or additives that can reduce the pH level so have been reading up about it here on the forums and on the web but I'm finding the more I read, the more questions I have... (probably doesn't help that I never went to high school and never learnt any chemistry!)

One good page I found that talks about skin pH is http://www.cwimedical.com/incontinence-skin-ph.html
Also http://www.millersoap.com/phtome.html which has been mentioned previously on the forum.

IrishLass - you suggest M&P base might be closer to neutral. Are you talking about a specific M&P base or any of them? 

I bought some pH strips before reading that they're likely to be quite inaccurate for testing soap so I thought even if I can't trust the reading they might still be useful in comparing CP soap & M&P soap pH.  I tested several different CP & M&P soaps and they all read roughly the same, around 8 to 9 with the highest reading actually a M&P soap.  I was expecting the M&P to be lower, not quite sure why though... I guess because I find M&P soap to be less drying on my skin than the CP soaps. But then, someone please jump in and tell me why. Is the level of "dryness" following usage is related to ingredients or pH?

The other thing I'm not clear about is the relationship between the lye and the pH. I get the impression many people think that if a soap passes a zap test then the pH is not too high (as in, not over about 11) but I am wondering if you can still have zap-free soap with a higher than usual/desirable pH or similarly have a soap that zaps yet the pH is actually normal for soap (ie. 9.5-10.5).  Is 'zap' directly related to pH? Does pH change over the course of curing?

I know this has been discussed on the forum time and again but it always seems that there is different information/opinions being thrown around.

If anyone can provide any good links to explain pH & soap in *plain english* that would be appreciated!


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## ohsoap (Oct 23, 2009)

My supplier told me that you can lower the ph by adding more Olive oil, and use beeswax to harden up the bar.  Most suppliers also sell ph strips, I've never used them though.  I do the zap test too.


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## xyxoxy (Oct 24, 2009)

I used test strips for my first few batches. But when I read up on their accuracy (or lack of) I decided I was wasting my time. I'm fine with a zap test. 

Unless I start making lotions I don't think it is worth the time and expense of investing in the more accurate ph test equipment that's available.


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## Bubbles Galore (Oct 24, 2009)

PH of 7 is neutral. Has anyone tried re-batching and adding Citric Acid to lower the PH? 

Some interesting reading for you:

http://www.newton.dep.anl.gov/askasci/chem00/chem00704.htm


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## soapqueen (Oct 24, 2009)

or would it be possible to add citric at the end og HP method (although I haven't tried HP yet).
Anyone tried it?


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## whisks (Oct 24, 2009)

ohsoap said:
			
		

> My supplier told me that you can lower the ph by adding more Olive oil, and use beeswax to harden up the bar.  Most suppliers also sell ph strips, I've never used them though.  I do the zap test too.



is the olive oil added in addition what one already has in the pot?
also, is it added while emulsifying or at trace?
thanks


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## carebear (Oct 24, 2009)

ohsoap said:
			
		

> My supplier told me that you can lower the ph by adding more Olive oil, and use beeswax to harden up the bar.  Most suppliers also sell ph strips, I've never used them though.  I do the zap test too.



As someone with a chemistry background and with daily access to chemists who, among other things, do some work with B&B products I can tell you that using more olive oil won't do squat to bring down the pH of the soap.  And there is absolutely no reason to then use BW to harden an olive oil soap as OO makes rock hard soap on its own.

pH strips lack accuracy for soap as well as relevance.  zap testing or testing for free caustic are the correct route.

doesn't matter when you add it = adding the OO with the other oils, at trace, or at the end if you are HPing won't do anything.  (and if CPing it doesn't matter if you add ANY oil at trace or with the other oils but that's a discussion for another time)


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## carebear (Oct 24, 2009)

regarding citric acid - I know that some have added very small amounts (adjusting their lye for it) to act as a chelating agent to reduce soap scum.  but if you choose to try it be careful because soap made more neutral = a salts and fatty acid sludge


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## Manda (Oct 24, 2009)

Thank you very much for that link Bubbles - it is very interesting stuff. I note they confirm you can add citric acid to reduce pH too.  It's just the method testing of the pH that seems so complicated and technical to me unless you have access to the proper equipment and lab!

Most people who have normal healthy skin can probably use most soaps we produce with no irritation or problem at all.  I think the main reason for wanting to lower the pH is to produce a soap which is going to be gentler on the skin of people who have sensitivities to high pH or who have conditions such as eczema or dermatitis. 

The Importance of Skin pH link I posted earlier talks about how people with skin conditions, and even people with other diseases such as diabetes, have a higher skin surface pH than normal already. By using a high pH soap it makes it even worse for their skin. Patients are often advised to use an acidic cleanser rather than an alkaline cleanser (soap is alkaline).


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## dagmar88 (Oct 25, 2009)

I'm sorry, but I just do not believe handmade soap PH can be controlled. As you said soap is alkaline; and there will be no way to change that characteristic. My opinion is that when you add something like lemon juice, citric acid, sulfur, etc.; you'll just end up with a slightly higher superfat. And ultimately, with slush...
And as, for example, extra virgin olive oils have a low acidity, this might have a slight effect on the ph of the soap overall.

My handmade soaps are currently used by people with skin conditions and diabetes and all are fine.



Mr. Y said:


> http://www.newton.dep.anl.gov/askasci/c ... m00704.htm[/url]]Question -   I am making cold-process soap (oils and fats plus sodium
> hydroxide)as a craft and was told by fellow soap-makers that I should PH
> test the soap after curing to make sure that all the sodium hydroxide in
> it has been neutralized.  I agree this is necessary to make sure it is
> safe to use, especially if I want to give-away soap to friends.



When your recipe was checked, checked, double checked, you superfatted as normal, the batch has cured, you're an experienced soaper and there's no problems like lye pockets; you just know your soap is safe and all NoAH has reacted. No need for a PH test to prove that.



Mr. Y said:


> http://www.newton.dep.anl.gov/askasci/c ... m00704.htm[/url]]First, what is an acceptable pH range for hand/body soap?  I have found
> numbers anywhere from 7 (I do not see how this would be possible) all the way up to over 9.



For me a non-issue. Not lye heavy = good soap.



Mr. Y said:


> http://www.newton.dep.anl.gov/askasci/c ... m00704.htm[/url]]Soap-makers suggest using a *tongue test* whereby the *taste* the soap on
> the end of their tongue to see if there is a *sizzle*.  First, this scares
> the hell out of me - chemical burns on the tongue are NOT on my top ten
> list of things to experience in this life and secondly, this can be a
> ...


Any soapers around here with seriously damaged tongues? Don't think so   It's not inaccurate, and some brush their teeth with it twice a day. Mine tastes kind of sweet.

_The partial answer from Mr S.

If the color is dark pink and the solution
clear, you have excess caustic - add a little more oil and cook your batch
some more.  _

with a good recipe, this will never happen.

_If it is colorless to yellowish but clear, your pH will be
fairly neutral.  If it is hazy, you have unreacted oil that you may want to
cook away with caustic.  _

So apparently, in the way the soap he knows is produced, superfat is not used. I presume the added citric acid would result in a small level of superfat and would indeed lower the ph just a bit. 

_If it is hazy AND pink, it is not done reacting
yet - cook it a little while longer and retest.  Very pale pink and clear
may indicate good results._

I CP and tests like this would be useless.
_
For body soap, a pH from 5 to 8 should be
mild to skin.  Higher pH values generally mean better cleaning of greasy
and/or oily soils.  A pH from about 8 to 10 seems fairly optimal for hand
soap.  If the soap is for laundry, a pH of 10 to 12 is acceptable._

Like we use more superfat when we want a gentle soap, and less to none when making a laundry soap.

_Do you see now why many soapers use the taste test they
learned from grandma?  (Excess oil tastes greasy, excess caustic tastes
(too) bitter.)  I hope this helps!_

Can't agree with that. I do not zap test cause it's too hard to test in another way. I do it cause it's sufficient for my goals. And my gran doesn't know one bit about soapmaking.

Another answer:

_It is practically impossible to remove enough of the sodium hydroxide from
home-made soap to render it safe to use -- or to offer as a gift. It cannot
be neutralized -- only "salted out" (at best, an unreliable removal
process).

I agree, the tongue test is dangerous. The alkali would make short work of
one's tongue._

Nothing shorts of nonsense IMHO...

As far as I'm concerend, this forum is a more accurate source of information  :wink: [/i]


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## soapqueen (Oct 25, 2009)

Manda said:
			
		

> Most people who have normal healthy skin can probably use most soaps we produce with no irritation or problem at all.  I think the main reason for wanting to lower the pH is to produce a soap which is going to be gentler on the skin of people who have sensitivities to high pH or who have conditions such as eczema or dermatitis.
> 
> I was just curious as to whether it was possible to lower Ph, to make a gentler soap for anyone. In my limited experience, CP soap made without adding surfactants or other chemicals, and only using EOs (no FOs), has cured mild eczema in 3 people I know, and is helpful to many others with eczema.


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## dagmar88 (Oct 25, 2009)

You can make a milder soap by superfatting and using oils that are considered conditioning. You can look those up over at www.soapcalc.net.


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## savondebilal (Oct 25, 2009)

*ahhh what is he talking about*



> Another answer:
> 
> It is practically impossible to remove enough of the sodium hydroxide from
> home-made soap to render it safe to use -- or to offer as a gift. It cannot
> ...



so what is this clown saying, that all our work with soap is in vain?!?!?![/i]


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## IrishLass (Oct 25, 2009)

*Re: ahhh what is he talking about*



			
				savondebilal said:
			
		

> > Another answer:
> >
> > It is practically impossible to remove enough of the sodium hydroxide from
> > home-made soap to render it safe to use -- or to offer as a gift. It cannot
> ...



Like what Dagmar88 said in response to this bizare pronounciation by Mr. Y- it's nothing short of nonsense. Our handmade soaps are rendered safe to use because we handmade soapers are smart and savvy enough to formulate our batches with a sufficient buffer zone of superfatting so that all of the lye molecules are reacted with the oils in order that the whole brew will be chemically transformed into soap molecules plus glycerin (whith an extra helping of unsaponified, moisturizing oils). Properly superfatted and cured handmade soaps have no more active lye molecules in them, and are perfectly safe to use. I have a friend that refuses to use anything but my handmade soaps because she says they got rid of her skin rashes. I don't think it very plausible that she'd be one of my biggest supporters if my handmade, properly superfatted soaps made with lye weren't all that safe and/or gentle enough. 


IrishLass


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## SilverMaple (Oct 25, 2009)

I have diabetics, eczema sufferers, people with psoriasis, and other skin irritations who are using my soap and seeing relief or at least no worsening.  So, the statements made by physicians that these people may need a low-ph cleanser may not be entirely true.  Some may, most won't.

The pharmacist in our small town inquired about my soaps, asking if I warned people with sensitive skin about the irritation the lye in the soap could cause... I gave her one of my brochures, a bar of soap, and explained the process to her.  

A week later she called me and asked me to bring some soaps down for display in the pharmacy gift area.  

There is a TON of misinformation regarding handmade soap floating around from various sources-- people who remember grandma's lye soap stinging, people who are terrified of lye, people who don't understand the process, and those who are affiliated with the detergent industry claiming their products are 'lye free' and thus safer to use.  Remember that it takes 50 positive comments to override one negative one-- so if someone is told by dozens of people that handmade soap is safe, then talks with one friend who had a bad bar irritate her skin, guess what she'll think is the norm?  Right-- the irritation.


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## ewepootoo (Oct 25, 2009)

I have added Kaolin Clay at up to 10% to some soaps with no visible effect on saponification. The clay has a pH of around 7 and I have a very accurate  pH tester which the boys in the lab at work tell me will give me a ballpark figure if I mix equal weights of something with Distilled water. Out of curiosity I will compare a couple of batches with and without Kaolin. I have Kaolin in different grades with pH ranging from 5 to 8. Steve


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## soapqueen (Oct 25, 2009)

I'll be interested to hear the results of this experiment, I often use clays.


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## Bubbles Galore (Oct 26, 2009)

soapqueen said:
			
		

> I'll be interested to hear the results of this experiment, I often use clays.



Me too Steve. I love clays in soap. Now I'm wondering about the different PH's in the different grades of clay.  :wink:


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## carebear (Oct 26, 2009)

Mr Y doesn't know squat about modern soapmaking LOL.

We don't "remove" lye - we react it and thus magic it into SOAP.

in the olden days (pioneer days) people salted out their soaps to help remove excess lye and to also harden their soaps.


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## ewepootoo (Oct 26, 2009)

Bubbles Galore said:
			
		

> soapqueen said:
> 
> 
> 
> ...


When the clay is being processed the pH is varied up and down by adding Sodium Hydrosulfite, Sulfuric Acid or Sodium Hydroxide the end product will have a pH to suit its use. Kaolin is used in paint,ink,plastic insulation,rubber,toothpaste,paper,cosmetics,pharmaceuticals and it is the main clay in porcelain.The glossy finish on your magazine pages is a coating of Kaolin Clay and I read where it is slightly radioactive. Just enough to trip the sensors used to pick up nuclear weapons entering US government institutions, it takes a truck loaded with magazines to trip these sensors. Steve


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## Bubbles Galore (Oct 27, 2009)

Thanks for that Steve. Interesting. I had no idea.  :wink:


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## ewepootoo (Oct 27, 2009)

I calibrated my tester and made up 2 small samples of the same pure Coconut Oil soap I made about 2 months ago, one of the samples was made up with 10% White Kaolin clay and is only a few days older than the one without the clay. I only made small samples of a few grams mixed with distilled water but they both came in with a pH of 9.8 and 9.9. Superfat was 5% on both, same tub of Coconut Oil.
Looks like the clay which has a pH of 7, has no effect on the finished product. Steve


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## carebear (Oct 27, 2009)

adding something with a neutral pH won't impact the pH of the original - diluting doesn't change the pH.


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## ewepootoo (Oct 27, 2009)

I have just been reading where you must dilute Sulfuric Acid with a pH below 1 with water at around 2000:1 to raise pH to somewhere near 3. Nasty stuff me thinks. Steve


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## Absinthe (Oct 29, 2009)

Stupid internet, can't find anything I want to quote 

I remember a recipe for soap that involved dropping a whole lemon (maybe more than one, can't remember) into a food processor then adding the result to the soap (I assume at trace) I think the point was for scent and texture but it would seem like there is a fair amount of acid in that and wondered why at the time it might even work at all. Perhaps the intended side effect was to lower the pH closer to 7 in that way. 

The fact that you can use cured soap on aluminum stuff suggests to me that the lye itself is not still active and all locked up in the alkaline salt we call soap. I am certain there is some minimum and maximum dilution at which the pH becomes lower. In effect, super-fatting a soap dilutes the "soap" with fat. Other non-saponifiables in the fats would also contribute to this dilution. 

So in effect the "soap" will be salt at its stable pH. However, your bar of soap (or bottle) is actually a mixture of "soap" and other things, including glycerine, left over non-sap things, fats that are not saponified and so on. 

So what you hold in your hand and say "This is soap" is really a matrix of "soap" and other stuff, bound together by the soap. 

I am not a chemist, nor do I play one on TV, but this is what I understand to be the case.


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## ewepootoo (Oct 29, 2009)

Dove soap is meant to have a near neutral pH but that is probably HP which I know less about than CP if that is possible. I dont know anything about rebatching but if all the Lye has been gobbled up and then you add something acidic to it this should lower the pH. 
I dont play a Chemist or even a Scientist on TV so best disregard any advice I may give unless it relates to repairing machinery. Steve


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