Ph Problem

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Mr.Clean

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I am making HP soap. I am using a soap calculator and following the recipe. I used phenothalene to test the soap at the end of cooking, and found it to be neutral. I poured the soap and cured for a few days. Now when I test it, it is no longer neutral. What's going on?
 
You're overcomplicating the matter a bit. After cooking soap, Phenothalene test result was clear. Waited four days. Phenothalene test result is bright pink.
 
No mr clean - you are over complicating it. Put the pheno away and use something more reliable, like a zap test.

Pheno is really unreliable as a test for lye, as you can see by the 'neutral' result followed by the alkaline result. A lot of pH testing methods are unreliable and don't actually tell you if your soap is safe or not.

Or are you thinking that some lye got in after the cook?
 
When used on something that is VERY alkaline, phenopthalene will turn bright pink but then almost instantly turn clear.

Soap is alkaline. It will always be alkaline. Phenol will turn pink because soap is alkaline. It will NEVER test neutral because soap is not neutral.

This is why there has been so much discussion about pH and how to test it and whether to bother testing it (I say don't bother). You don't need to know if your soap is alkaline, we already know that it is alkaline because it is soap. What you are trying to find out is if your soap has any excess lye, and pH testing will not tell you that. Not with strips, not with phenol.

Zap test will tell you if you have excess lye.
 
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Please forgive me but. . .

People who make bar soap - throw away your drops, test strips and meters - they do you no good at all!

I'd like to ring the neck of the authors of all those soaping books that tell people to do such a stupid thing!!
 
I agree with Seawolfe and the good Gent and the others. How did you conduct the test with the phenol? I ask because to properly test with phenol, one must make a 1% solution out of 1 gram soap dissolved in 99 grams distilled water, and then you add the phenol drops to that (most soapers I've seen testing with phenol just drop the phenol onto their soap, which is the wrong way to do it). But even if you do it correctly, it is hard to judge the pH unless you have a really good eye for different shades of pink since pheno turns various shades of pink from 8.2 pH to 12 pH, and is clear from 0 - 8.2 pH, and also clear again over 12 pH.


IrishLass :)
 
Please forgive me but. . .

People who make bar soap - throw away your drops, test strips and meters - they do you no good at all!

I'd like to ring the neck of the authors of all those soaping books that tell people to do such a stupid thing!!

THANK you. Although I've used test strips to test mystery liquids oozing from my soap (I am not touching that with my tongue on new soap). pH 14? Probably lye water. pH lower than that? Probably oil/lye mix.

Still, the result is the same. Rebatch. The only reason I tested was curiosity.

I use exactly the same test on every batch I make--the zap test. Then I test a bar before even thinking about letting anybody else use it.

Since I don't yet look like the Cryptkeeper from Tales From the Crypt, I figure I'm doing OK. So far. You never know.
 
I apologize if I'm coming accross as being short. Simply put, and however you want to determine the ph, it is too high. I know this because I have used the soap, I have used Phenothalene many times, and while it is not a perfect indicator, it will serve well enough. How I know the ph is too high is not the point. It is. What I want to know is why is it not at the time I pour, but when I test and or use the soap, it is not high. It's far to high.
 
I apologize if I'm coming accross as being short. Simply put, and however you want to determine the ph, it is too high. I know this because I have used the soap, I have used Phenothalene many times, and while it is not a perfect indicator, it will serve well enough. How I know the ph is too high is not the point. It is. What I want to know is why is it not at the time I pour, but when I test and or use the soap, it is not high. It's far to high.

What do you feel is too high of a PH for soap?
 
I don't see how the alkalinity can rise between pouring and curing, unless more alkali was added.
 
Oh my. I don't have any better way to describe what is happening. I thank everyone for their help. Have a good afternoon!
 
Oh my. I don't have any better way to describe what is happening. I thank everyone for their help. Have a good afternoon!

Okay, I'm going to give you an answer, but you won't like it. Ignoring that PH is useless to determining soaps safety, your question was why the PH raised after you molded and cut the soap but wasn't high when you poured the soap.

The answer is, it did not get any higher unless you added more alkaline solution to the soap. You said you did not and so, although you tested the soap, the only possible answer is that you tested incorrectly.

Your soap has not mysteriously become higher in PH.

Now if you are saying your soap is lye heavy, that is a whole different question.
 
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Thank you for listening. I don't feel like writing an hour long post today. The soap burns. Simple. Didn't after cooking. Also tested clear. No alkalinity added later. It was "neutral" when made. It's not now. This has nothing to do with anything other than the fact that the soap is becoming more caustic. I have used shaving soap long enough to know when it's not and when it is caustic. If you cannot answer-fine. But please get off the method of determining the ph.
 
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Is it possible there was a section of soap that wasn't as well-mixed, still had active lye, and separated slightly to the top of the soap during the set up phase?

I've had similar problems because I don't have a crock pot to dedicate and use the stove on low heat. Heating is uneven, my mixing isn't the best, and...well, I really don't like HP and only use it for batch rescue, so I spend the entire period rushed and annoyed. Usually mine is just a little separating oil that absorbs quickly, but I suppose you could get a lye pocket that rises up.
 
I was using a crockpot. I also wonder about that. Perhaps a pocket of lye did not get incorporated into the batch. I know I had very clear neutral indications before I molded the soap, but am now getting very different indications. This is t the first time I have had this happen. That's the bigger problem. I can toss a batch, but I need to fix the process.
 
I was using a crockpot. I also wonder about that. Perhaps a pocket of lye did not get incorporated into the batch. I know I had very clear neutral indications before I molded the soap, but am now getting very different indications. This is t the first time I have had this happen. That's the bigger problem. I can toss a batch, but I need to fix the process.

I can't tell you if that's even a possibility as I simply don't have enough experience with HP. If it is, I'd guess it was simply not stirred quite 100%, an easy fix.

However, experience with CP indicates that very, very mild separation tends to correct itself if left alone. Give the soap several days to settle down, then zap test it. If it passes, put it away to cure as if it were CP and give it four full weeks (really, I suppose one should do that with HP anyway).

If it doesn't pass, test it again in a few more days. If it still fails, rebatch with added oils to get rid of the zap--and plan on using this one as a home soap only. I never trust failed batches as gifts.

Now if we're talking visible puddles of liquid atop the soap that aren't absorbing, that's a different story.
 
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