Zap Test - what is it?

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Franne

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I'm new to soaping and have read that you should test the PH of your soaps. A lot of what I've read on this site mentions the 'zap' test. What is that and how do you perform it? I also read about some chemical (can't remember the name now but I think it started with a 'T') was also useful in determining PH. Also, I'm of the impression that an ideal PH is around 9. Is that correct? Any input is welcome!!!
 

The Efficacious Gentleman

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Testing the pH of soap is an interesting topic. Many people swear blind that you must do it, but I don't see that it tells us anything of interest. Not to mention that accurately testing the pH requires more work than many are willing to go to, so it makes the results to be a none-sense.

You are right that most soaps that we make will have a pH in that area, + or - a bit. But what is important is if the soap is safe or not, and pH testing falls over here because it doesn't tell us that.

A soap is unsafe when there is lye that is not saponfied, so it is still lye. A soap with a pH of 11 could be safe or unsafe, depending on whether or not there is still lye present. Which is where the zap test comes in!

Your tongue will react to this lye in a similar way to when you place a 9volt battery on it - a zapping feeling. My personal method for testing is:

1 - I wet a finger and rub it on the soap. I wait to see if it tingles or not. When not...............

2 - I put the wet finger on the tip of my tongue. If it zaps, lye is still there. When not..................

3 - I touch the soap itself to my tongue.

This tells me if my soap is safe or not, from the point of view of lye.

Which then makes me wonder - what does the pH help me with? People have heard so much about Dove and so on and how soap is bad for you. But all of our soap will be above pH 7, so the test is for safety, which pH can't tell you.
 

Susie

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There is a sticky for that:

http://www.soapmakingforum.com/showthread.php?t=30690

And I am a dedicated zap tester. I just need to know if my soap is safe. And pH testing of bar soap is prone to errors as you must dilute X amount of soap to Y amount of water, and you have to stress if there is some undiluted soap...not for me.
 
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Franne

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Thank you!

This has finally put to rest, for me anyway, the need to PH test. I will not be using it as I agree with you. It doesn't tell us if the soap is SAFE! However, I will apply the zap test as you described it. Thanks so much for getting back to me so quickly!:wave:
 

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