pH issues /// how to lower

[kaaty]

hello, my name is Ralu and I'm new here. I'm new in soapmaking too .
Although I searched everywhere for some answers concerning influencing soap pH i couldn't find any good answers.
So. plsss..if you know, my questions is:

How can I adjust my soap pH ? Is it a matter of oil mixing temperature? Or is it a matter of water/lye ratio ?

I'm asking that because i cannot lower my pH under 10.5 and many soapmakers in my country say that they obtain 8 or 9, even 7 sometimes...HOW ? Nobody tells me :shock:

Thank you very much and I hope you receive me in your beautiful community here.

PS: sorry for my mistakes in english. it's not my native language. thank you for understanding.

 

[Fragola]

they obtain 8 or 9, even 7 sometimes...HOW ? Nobody tells me Shocked

I'll tell you how - they are measuring it wrong. If I had to guess, they are using pH strips, and some of them can be extremely unreliable.

Pure soap has a pH around 10. Are you using pH strips aswell? What brand name ?

For liquid soap, you can easily adjust pH by adding citric acid and using a pH meter. For solid soap, it's not worth the effort.

Question is what is your goal? If your purpose is to obtain a milder soap, change your recipe / adjust your superfat level.

 

[Genny]

Regular CP soap has a ph of in between 8.5 -10.5

Trying to lower it can break down the soap. Also, lower ph doesn't mean better for the skin.

 

[kaaty]

Thank you very much for answers.
Yes, i'm using pH roller bands but no name. we don't have brands for trat here. I have 3 roller in a case - the one i'm using is for the interval between 9 and 13 and the color i always obtain is around10-10.5. i thought i was doing it wrong.
My goal is to have a soap that nourishes and care the skin without drying it.

I thought that a milder soap is a lower ph soap.
I tried more than once the same recipe...but one time dries the skin and other times doesn't it't strange.

Do you think the same recipe - one mixed at a temperature of 42grades Celsius will be the same as one mixed at 37 grades Celsius ?

thank you

 

[kaaty]

Regular CP soap has a ph of in between 8.5 -10.5

Genny, thank you, dear... it's very important to understand the process.
if is between 8.5 and 10.5...there is a way to obtain 8.5, right ?
A value of 8.5 is randomly obtained ?

 

[sabon]

soap pH

Hi I am new to this forum but have recently been testing the pH of different commercial soaps and the recent batch of soap I made (one the CP and the other HP) to satisfy my curiosity.
Here is what I noted in the handmade soap

HP
pH lye water solution 14
pH at trace 10
pH before pouring into a tray 9
pH a day after 8
pH after 2 weeks 7

With CP I tested the pH after 48 hrs and it was 9
a week later 8
and after 15 days its between 7 and 8

So what I understood was as the saponification progressed the pH reduced making the soap milder.
And I am guessing if the pH is very high, then there is still some lye left which is yet to complete saponification.

 

[JewlsMS]

Nice experiment Sabon! Very interesting.

 

[carebear]

what did you use to measure the pH of your soap. http://www.millersoap.com/phtome.html

because, sadly, soap is by its very nature an alkaline beast. at a pH of 7 it falls apart.

 

[Fragola]

Yes, sadly ... The results are still interesting, though. Maybe your measurement error is increasing with water content decreasing.

if is between 8.5 and 10.5...there is a way to obtain 8.5, right ?
A value of 8.5 is randomly obtained ?

Personally, I was able to obtain a lower value by rebatching soap together with fruit juice.

With a soap with a pH of 8.5 I would be worried about spoilage and consider adding a preservative. There are much more bacteria growing at 8.5 than 9.5.

 

[judymoody]

My soap is generally between 9-10 and I typically superfat between 8-10% depending on the recipe. So far, no complaints.

 

[IrishLass]

Ditto what carebear said. If you are getting a pH reading of 7 for your lye-based soap, and it is still in its normal, solid form and hasn't lost any of its ability to clean, you can be 100% absolutely sure that your pH measuring device is faulty and way off the mark. Like carebear said, soap (lye-based soap) falls apart and is no longer soap at a neutral pH of 7. That's because soap by it's very definition is an "alkaline salt of a fatty acid". Even though the pH does drop some during cure, it will always fall on the alkaline side of the scale.

Even though it's pH will never be neutral, if the lye-based soap is properly made, it will become what is known as 'tongue-neutral'. This means that the soap will not cause a 'zapping' or stinging reaction to occur when the tip of one's tongue is pressed against the soap (i.e. the 'zap test'). Such tongue neutral soap may have a true pH as high as 10.5 or 11, but is perfectly safe to use and may even feel quite mild to the user's skin.

From all I've read, it is my belief that mildness is not exclusively a pH-related issue. There are other factors at play, such as the types of oils that go into the mix. Some oils -such as coconut oil, PKO and babassu oil- are more highly cleansing in soap than other oils and can cause irritation depending on how much of them are used, and also upon the user's individual skin-type.

In Dr. Kevin Dunn's book Scientific Soapmaking (page 371), he brings attention to some reference reports from an 'irritability index' that list the irritability level of certain commercial soap bars. The least irritating soap in the tests was Johnson & Johnson's Baby Soap w/oatmeal. Any guesses as to the soap's pH? According to the index, it's 12.35. The most irritating soap in the tests was Camay Gala. It's pH? If you think it's higher, you would be wrong. It's pH is 10.36. Very interesting stuff.


IrishLass

 

[sabon]

In Dr. Kevin Dunn's book Scientific Soapmaking (page 371), he brings attention to some reference reports from an 'irritability index' that list the irritability level of certain commercial soap bars. The least irritating soap in the tests was Johnson & Johnson's Baby Soap w/oatmeal. Any guesses as to the soap's pH? According to the index, it's 12.35. The most irritating soap in the tests was Camay Gala. It's pH? If you think it's higher, you would be wrong. It's pH is 10.36. Very interesting stuff.


IrishLass

This is interesting.

 

[kaaty]

This is great, thank you for the information you shared.
So...my conclusion is that somebody tells me that has ph 7 and the soap looks like a soap...it's a mistake of measurement

 

[carebear]

if it is true soap, they are wrong (whether they got wrong information or measured incorrectly).
if it's a syndet (synthetic detergent) entirely or largely, then it could be 7.

pH is not an indicator of skin-friendly, by the way. yes your skin has an acidic layer on it (the acid mantle), but even water alone disturbs that. and it's quickly regenerated anyway.

 

[dryalligator]

:?:
If thats true, how are you to measure ph? I use a pool testing kit with a color range and my soap after a week measures 7.5-8.5. I zap test before measuring and all I taste is faint salt.

 

[IrishLass]

:?:
If thats true, how are you to measure ph? I use a pool testing kit with a color range and my soap after a week measures 7.5-8.5. I zap test before measuring and all I taste is faint salt.

This Link that carebear posted above will help answer your question.

IrishLass

 

[kaaty]

Thank you for the link. it's very usefull for me too.