When we launched our solid shampoo bars at the end of 2020, we started to receive many questions about what we meant by saying that our shampoo bars are soap-free. We know it can be difficult to understand the world of shampoo bars, therefore I decided to write a short blog post explaining the difference between Soap-based and Soap-free shampoo bars and how to tell them apart.
Today, there are many shampoo bars on the market, but they can all be classified into two major groups: soap-based and soap-free (also called pH-balanced) shampoo bars.
Both will state "Shampoo Bar" on the label; however, they are two totally different products with different chemical compositions and very different results.
I will spare your time and say it right away, it's the soap-free shampoo bar you want!
As a soap maker myself, I totally adore natural cold-process soap, but most definitely not for my hair.
Chemistry
Soap-based shampoo bars are technically soap. They tend to contain more nourishing oils and plant butters than hand & body soaps, but in terms of chemistry, these bars are soap. Soap is made by the saponification process, where lye solution (sodium hydroxide + water) interacts with fatty acids (oils, butters, sometimes lard) and results in soap.
Soap-free shampoo bars do not undergo a saponification process, therefore are soap-free. These bars are made using surfactants, conditioners, and hair-loving ingredients, such as panthenol, nourishing oils, and botanicals.
I know that the word ‘surfactant’ can make some cringe, but not all surfactants are made equal. SLS (Sodium lauryl sulphate) although commonly found in commercial shampoos is inexpensive but very much oil stripping and is best to be avoided. If you would like to go completely sulphate-free, then you should also avoid SLES (sodium laureth sulphate) and SCS (Sodium coco sulphate).
But then, there are also milder, plant-derived versions, for example, Sodium Cocoyl Isethionate which is readily biodegradable, and also a sustainable option.
So, why choose soap-free?
It's all about the pH! Our scalp is an acidic environment with a pH level between 4.5- 5.5 and needs a pH-balanced product to maintain optimum pH levels.
Soap-free shampoo bars are pH balanced and have pH levels between 4 – 6 (ideal for hair & scalp), while soap-based bars have a naturally high pH of 9-10.
Why pH matters?
To maintain healthy hair and scalp we need our hair cuticles to lie flat. High pH products like soap, can leave the cuticles open which results in friction, tangling, and even damage over time as they rub against each other. Open cuticles also reduce shine and make the hair appear dull.
Soap-free (pH balanced) bars have scalp-friendly pH which helps cuticles to lie flat resulting in healthy-looking and shiny hair.
If both products are called 'shampoo bars', how can we tell them apart?
Soap-based shampoo bars will either have sodium hydroxide (lye) in the ingredients list or will have the saponified version of ingredients listed, such as:
- 'sodium olivate’, which means saponified olive oil
- 'sodium shea butterate’ – saponified shea butter
Soap-free shampoo bars will contain a much more complicated list of ingredients, including surfactants, emollients (moisturisers), conditioning agents, and others.
Bear in mind that not all soap-free bars are the same. If you have any doubts always contact the maker who can explain the ingredients and confirm whether the shampoo bar suits your needs.
If you want to LEARN HOW TO MAKE SHAMPOO BARS, visit our learning resources here.
