Measuring pH in cp soap

[The Efficacious Gentleman]

I don't pH test, for two reasons -

1, to do it properly sounds like a pain. Getting a solution of the correct strength accurately each time as well as using all the correct bits and pieces.......and if I am going to do it, I should do it properly or it really makes a nonsense of it.

2, pH doesn't tell me what I need to know. As DeeAnna said, the pH of a soap with no unsaponified lye varies a great deal. So when I have my pH measured and I have a number, it tells me the pH. I need more information to know if that means the soap is safe or not.

Zap testing tells me whether or not my soap is safe. That is what I need to know. The pH alone does provide this.

For those with doubts on this, please tell me exactly what pH my soap should be - not a range, mind you, I'm looking for "a pH less than or equal to x is safe. Greater than x is unsafe" and this needs to apply to any mix of oils/fats.

As for the risks of zap testing, I rub a wet finger on the soap and wait to see how it reacts. Then I dab the finger on my tongue. Then I touch the soap to my tongue. Coupled with the fact that I accurately measure and am very careful about my process means that the risks are severely reduced. I think I do more damage eating piping hot pizza than I do testing for zap!

 

[new12soap]

Zap testing is widely accepted as the easiest and most reliable method for the layperson home crafter to test for excess lye. Anyone that is not comfortable with that method should not use it! It is by no means necessary. I don't do it.

Katz, what you are experiencing is exactly the problem with trying to pH test soaps. Yes, the source you linked, millersoap, is very reliable IMO. pH test strips simply do no work for soap. You yourself said you are getting readings of 7-8 and that is just not possible. Soap is by its nature an alkali, if the pH was that low you would not have soap, you would have a gooey gloppy mess.

As the chart posted by DeeAnna illustrates, true soap can have a pH as high as 12.4 and still be perfectly safe to use and contain no excess lye. So I ask again, what is the purpose of trying to test your soap's pH? It is very difficult (nigh on impossible as far as I can tell) to get an accurate reading, and even if you do get one, that doesn't tell you anything useful.

I think this may be another one of those times that (probably) well meaning folks have passed on what they have learned, that you should test pH and get a low reading, so folks continue to believe it and pass it on to others. I do not believe it should be used at all, but again, JMNSHO

 

[DeeAnna]

Hey, may I ask that everyone take a deep, quieting breath, please? I'd like to gently suggest that we return to debating the topic on a factual basis or let this thread fizzle down to a quiet end. And to that end, may I add a wee bit of humor -- kung fu catfighting....

 

[shunt2011]

Hey, may I ask that everyone take a deep, quieting breath, please? I'd like to gently suggest that we return to debating the topic on a factual basis or let this thread fizzle down to a quiet end. And to that end, may I add a wee bit of humor -- kung fu catfighting....

I couldn't agree more!

 

[sassanellat]

Hey, may I ask that everyone take a deep, quieting breath, please? I'd like to gently suggest that we return to debating the topic on a factual basis or let this thread fizzle down to a quiet end. And to that end, may I add a wee bit of humor -- kung fu catfighting....

*snickers* I love cats (and dogs). And as I noted in my last post, I've said everything I needed to say on this subject, and I'm only replying specifically because you posted cats (and dogs)!!

 

[LBussy]

I'm only replying specifically because you posted cats (and dogs)!!

 

[Susie]

*chorlesnort*

 

[judymoody]

If I can add a common sense suggestion - the first thing you should do is look at your soap. Does it have a smooth even firm consistency? If so, it is likely that the zap test will be uneventful.

However, what if there are there oozy pockets? Are there any visible crystals? Is white or crystaline residue forming on cut surfaces? If the answer is yes to any of those questions, I wouldn't do the zap test. Clearly the soap has a problem and your tongue is not going to thank you for proceeding. In these instances, I'd attempt a rebatch if I were confident in my measurements, or pitch it if I weren't.

Regarding what the original poster asked, I agree with DeeAnna (don't I always? ) There are so many soapers who post because they want to attain an elusively low pH under the misguided idea that a more pH neutral soap is somehow better. If it's lower than 8.5, it's likely a mismeasurement. Trying to bring it below that will yield unstable soap. However, if it's above 11-12, you might want to rethink your recipe.