Is Liquid Soap an Acid or Base?

Did you know that liquid soap is a base? Don’t believe it? Join us on a journey of soap science. Here, we are going to reveal the truth behind the pH levels of this cleansing soap.

From pH levels to the science of cleansing, this article will give you a deeper understanding of the soap in your bathroom. So, grab a bottle of the cleanser and join us on this enlightening journey of soap-science and pH balance.

Is Liquid Soap an Acid or Base?

Is liquid soap an acid or a base?

Let’s read in detail: is liquid soap an acid or base or neutral? Basically, soap solution formulates for different purposes. Therefore, it acts too basic or too acidic in different conditions. But in most cases, liquid cleanser is mildly base.

However, still you may be struggling to determine the type. Hence, we have prepared a comparison table of the most common watery cleansers. Hope it will remove your doubts and confusions. Check it out.

What is a liquid soap base?

Basically, liquid soap base is made of ingredients such as water, oils (e.g. coconut oil, palm oil, castor oil), glycerin, Lye. Lye is also known as potassium hydroxide.

Here,  Potassium hydroxide works as a strong alkali that saponifies the oils to create soap. Besides that, glycerin is a vital component of the saponification process. It helps moisturize the skin.

Initially, these are combined to create a stable, liquid consistency. After that,  fragrances, colors, or other ingredients are added to the base.

The saponification is the chemical reaction between fat and alkali to make soap.

Is Liquid Soap an Acid or Base

What type of base is soap?

In general, soap is a base. But have you ever thought about what type of base the soap is? Basically, if Sodium Hydroxide works as base in soap, it is considered as a strong base.

On the other hand, in some households cleaner ammonia works as a base. In this case, the cleaner base is considered as a weak base. 

Is liquid soap pH-balanced?

Generally, the pH of any substance depends on its acidity or basicity. A pH of 7.0 means neutral; a pH less than 7.0 means acidic; and a pH greater than 7.0 means basic.

pH = 7.0 = Neutral

pH < 7.0 = Acidic

pH > 7.0 = Basic

According to this constant parameter of pH, liquid soap is a base. That means, it has a pH higher than 7.0. However, the pH of this type of cleaning solution can vary. It depends on the specific formulation and ingredients.

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Which soaps are pH-neutral?

Fundamentally, the pH of a pH-neutral soap is around 7.0. As a result, it is considered as neutral on the pH scale. (Neutral means that it is neither acidic nor basic.)

Again, there are a few different types of pH- neutral soap. For example, castile soap, glycerin soap, and soap.

For your convenience, here we have made a comparison table of castile soap, glycerin soap, and pH-neutral surfactants. Take a look.

Please note that the pH of these soaps can vary depending on the specific formulation and ingredients used. It’s because some soaps may be more acidic or basic than others.

How do you check the pH of liquid soap?

To explore, is liquid hand soap acidic or basic; you can check the pH by yourself. In that case, you need to follow some steps. But before that, you have to ensure the materials you need to test.

Principally, there are several ways to check the pH of a solution, including: pH strips, pH meter and pH indicator.

The material you need are followingly:

  1. a bottle of liquid soap,
  2. pH paper, or a pH meter, pH indicator
  3. a clean container,
  4. and distilled water

Checking pH with pH strip

To use pH strips, follow these steps:

  1. Dip the strip into the solution for about 1-2 seconds.
  2. Remove the strip from the solution. then shake off any excess liquid.
  3. Compare the color of the strip to the color chart provided with the strips.
  4. Record the pH value of the solution.

Notably, pH strips are not very precise. Apparently, they are only meant for rough estimates of pH. In case you need a more accurate measurement, you should consider using a pH meter.

Checking pH with pH meter

If you want to use a pH meter, follow these steps:

  1. First thing first, make sure the pH meter is calibrated with the appropriate buffer solution.
  2. Turn on the pH meter.
  3. Let it warm up for a few minutes before taking a measurement.
  4. Clean the electrode of the pH meter with distilled water. Then dry it with a clean towel or tissue.
  5. place the electrode into the sample solution. Wait for the reading to stabilize.
  6. Record the pH value of the solution, which displays on the pH meter.
  7. Clean the electrode with distilled water and dry it again after each use.

Calibrating means making sure a measuring device gives accurate results by adjusting it to match a standard measurement.

Note that, it is best to avoid turbulent liquid or bubbles while taking the measurement.

Moreover, you should also make sure that the pH meter is properly calibrated (like weekly) before each use.

Again, it is important to take a record of the reading for traceability.

Checking pH with pH indicator

To use a pH indicator, follow these steps:

  1. Some common pH indicator solutions include litmus, phenolphthalein, and methyl orange. First, choose any of them.
  2. Secondly, Add a small amount of the indicator solution to the sample you wish to test.
  3. Then, Observe the color change of the indicator in the sample.
  4. Finally, Compare the color in the sample to a color chart to determine the pH of the sample.

On the whole, it is important to follow the instructions of the indicator. Because, different indicators have different ways of preparing. So, Make sure to prepare a fresh solution of indicators each time you are using it.

Things to be concerned about while testing:

However, pH measurement of a solution can get affected by temperature. Therefore, it is important to ensure that the solution is at the correct temperature before measuring.


In summary, A simple pH test can confirm that liquid soap is a base with a pH level above 7. Moreover, this simple test helps to find out whether the soap is eligible to serve your purpose or not.

So, test it by yourself and confirm its eligibility.

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You certainly can’t believe everything the Internet tells you. Kelvin David knows this better than anyone. A few years ago, Kelvin decided to try online shopping for the first time. He was looking for a new electric drill he could use on his daily work as a contractor.