Colorants for High pH CP Soap

For Cold Process (CP) soap, which has a high alkaline pH, choosing colorants that are stable in alkaline conditions is very important to prevent color distortion or fading.

Based on the information found, there are some colorants that should be suitable for use in CP soap and have fade-resistant properties:

• Orange: We recommend D&C Orange No.4 (CI 15510) EasyWash™. This is a water-soluble orange colorant specified as a special type that is non-staining (Easy to Wash) and resistant to fading.
• Red: There are several options in the EasyWash™ series that are interesting, such as:
  • Ponceau 4R (CI16255) EasyWash™
  • D&C Red No.33 (CI17200) EasyWash™
  • FD&C Red No.4 (CI 14700) EasyWash™
    
    Colorants in this group are water-soluble and are stated to be fade-resistant, which is a desired property for CP soap.

In addition to the EasyWash™ colorants, generally, Pigment type colorants like Iron Oxides (red, yellow, black, brown) are also popular and highly stable in CP soap.

We recommend testing the colorants in small amounts in a small batch of CP soap first to check the color stability before full-scale production.