Handmade Soap QC Indicator - PH Value Demystification

It should not be difficult to understand that the raw materials of soap contain alkaline agents, which are necessary for saponification, so soap is alkaline.

About PH

Simply put, it's the pH.
It is usually expressed as a value from 0 to 15.
7 is neutral, the greater the 7, the more alkaline it is, the smaller the 7, the more acidic it is.
Take a look at the table below:

Therefore, what is the pH value of the soaps commonly found in the market, whether they are factory-made or handmade soaps?

After random sampling of the actual measurement found that, whether it is a well-known fragrance soap, Japanese soap, big brand soap, or YUNASOAP handmade soap, the measurement results fall between 9 ~ 10, which is a stable soap products should have the PH value.
If the value is too high (greater than 11), it means that saponification is not complete or there is too much alkali remaining.

Top left: AGRARIA
Upper right: Natto alkaloids from Japan
Below left: YUNASOAP Left Handed Cream Soap
Below right: L'Occitane Milk Soap

Then you may have heard some operators claiming that their handmade soaps have a pH value of 8 to 9, or even a condition below 8. As mentioned earlier, soaps are made from alkaline aqueous sodium hydroxide solution, and it is impossible for them to have this number unless an additional acidic substance is added to neutralize the pH value.
This experiment was tested using an aqueous solution of 1%, i.e., the same amount of water was added to an equal weight of soap, dissolved in water and then tested with theTemperature DisplayThe pH value is measured by a professional pH tester (temperature variations may also affect the ph value).
After the instrument is put into an aqueous solution, wait until the value stabilizes and stops jumping, and the number displayed will be its pH value.

Most tradesmen or handmade soap players use theAcid-alkali Extensive Test StripsmaybePhenolphthalein IndicatorInstead of using a test instrument, the measurements were made with a large amount of error and misinterpretation.
It is thought that the pH value of soap should fall between 7 and 9, or it is thought that below 9 is a good soap.
[Note] Acid-Base Extensive Test Paper: Test paper commonly used in science and chemistry classes in high schools in the United States. The pH value is determined by applying a solution to the test paper and comparing the color of the paper to the area on the colorimetric scale after color development.

In fact, the acid-base characteristic of soap is about 9 to 10.5.
If it is less than 9, the soap will become unstable and lose its cleaning power.
If soap loses its cleansing power then it's not the role soap should have.
Have you been playing with handmade soap or using handmade soap that
I hope that after reading this post, the myth that the PH should be less than 9 is gone.
To understand the characteristics of the product clearly in order to keep the quality of the product stable.
The pH value of handmade soap is an important quality control indicator!