TESTING THE PH OF SOAP

Testing the pH of soap is a common practice among soapmakers to ensure that the soap is safe and suitable for use on the skin. The pH level indicates the acidity or alkalinity of a substance. For soap, a pH level between 8 and 10 is generally considered acceptable for skin contact.

Here’s a step-by-step guide on how to test the pH in soap:

Materials Needed

• pH Test Strips or pH Meter: pH test strips are readily available and easy to use. pH meters are more accurate but may require calibration.
• Distilled Water: Use distilled water to ensure that the testing is not influenced by impurities.
• Soap Sample: Cut a small sample of your soap. This can be a sliver or a shaving from the soap bar.

Procedure

• Prepare the Soap Sample: Cut a small piece of soap, ensuring that it is representative of the entire batch.
• Dissolve the Soap in Water: Dissolve the soap sample in distilled water. This can be done by grating or shaving the soap into small pieces and allowing it to dissolve in a known volume of distilled water. Use enough water to ensure thorough dissolution.
• Mix Thoroughly: Stir or shake the soap solution thoroughly to ensure that the soap is completely dissolved in the water.
• Prepare pH Strips or Meter: If using pH test strips, dip a strip into the soap solution. If using a pH meter, immerse the electrode into the solution.
• Wait for Color Change or Reading: Allow the pH test strip to react with the solution for the specified time (usually a few seconds). For a pH meter, wait for the reading to stabilize.
• Compare the Color or Read the pH Value: If using pH test strips, compare the color of the strip to the color chart provided with the strips. The color corresponds to the pH level.
• If using a pH meter, read the pH value directly from the meter’s display.
• Interpret the Results: A pH level between 8 and 10 is generally acceptable for soap used on the skin. If the pH falls within this range, your soap is suitable for use. If the pH is higher or lower than desired, adjustments to the formulation may be necessary in future batches.
• Note Any Additives: If your soap contains additives like fragrances, essential oils, or colorants, be aware that these can impact the pH level. Some additives may increase the alkalinity of the soap.
• Repeat if Necessary: If you have concerns about the accuracy of your first test, you can repeat the process with a new soap sample and fresh pH test strips or a calibrated pH meter.

Remember that pH testing is just one aspect of quality control in soapmaking. It’s important to consider other factors, such as hardness, lather, and skin feel, to ensure that your soap meets your desired specifications.