The reason why I'm writing this article is because I see so many people wrecking their beautiful hair with aggressive alkaline substances like 'natural' baking soda, 'shampoo-soap' bars or hair products with liquid castile soap.
I did the same thing many years ago when I washed my hair with home made soap. Eventually it got so dull and lifeless that I stopped using soap on my hair.
And no, rinsing with apple cider vinegar after washing with soap doesn't help but it actually makes it worse, because the rapid change from alkaline to acidic pH really destroys the delicate structure of the hair shaft over time.
And here is why.
You probably already know from science class that a low pH is acidic and a high pH is alkaline, while a pH of 7 is neutral on a scale that goes from 0 to 14. Because the scale is logarithmic, a pH of 2.0 is ten times more acidic than a pH of 3.0.
But what pH is healthy for your skin and hair and why does it matter?
Human hair consists primarily of keratin molecules arranged in a hierarchical sort of structure, which is one of the most complicated structures in the body and is made up of two separate parts: the hair follicle, which exists below the skin, and the hair shaft, which is the hair that we see.
In the hair shaft, there are three main regions: medulla, cortex and cuticle.
The innermost layer is called the medulla. Depending on the type of hair, the medulla isn't always present. It consists of hollow spaces of air and round cells. Thicker hair usually has a medulla while in fine hair it is missing.
The middle layer is called the cortex, which makes up the majority of the hair shaft, about 70-95%. It is composed of bundles of fibrous coils made of keratin protein molecules that give the hair strand its strength, elasticity and shape. Both the medulla and the cortex contain pigments that are giving the hair its color.
The outermost layer is called the cuticle, which consists of multiple layers of an overlapping structure of keratin scales that protect the cortex and medulla.
Now this is where the importance of the pH comes in.
There is a very thin fluid layer composed of oil, water and salt called the mantle which covers both the hair and the skin. This mantle is supposed to be mildly acidic with a pH of 4.0 - 5.5
If the acidity is right, the scales of the cuticle lie flat and smooth on the cortex, which makes your hair shiny, healthy and resilient and prevents it from loosing moisture.
Alkaline products cause the hair to swell, the cuticle to lift and they remove oils from the hair. This results in frizzy, dull and brittle hair that is prone to breakage and tangling.
Have you ever bent a wire back and forth rapidly to break a piece off?
This is what happens when you repeatedly disturb the pH balance of the hair shaft by washing with baking soda and then rinsing with vinegar. The hair shaft swells and contracts, the protective mantle gets washed off and the cuticles and cortex become exposed and slowly erode, not right away, but over time.
Those extremely alkaline solutions used to perm or relax hair cause the bonds between keratin protein molecules to break down and can eventually dissolve the protein completely.
This is a damaged hair with the little scales breaking off:
Mildly acidic products harden the outer layer, flatten the cuticles, and shrink the diameter of the hair. This serves to make the hair glossy, shiny and less prone to tangling and snagging on other hair strands.
Hair that is close to its ideal pH of 4.0 – 5.5 is at its peak strength.
Shampoos and conditioners that are mildly acidic also have been noted to provide longer life to the color of hair that has been dyed.
That's one of the reasons why kombucha is so amazing for your hair, it is less acidic than vinegar but has just the right pH to be beneficial.
I've been asked why my hair products are not just neutral with a pH of 7 but are more on the acidic side. It's because even plain water is still too alkaline for hair.
For those of you who are already fans of the Kombucha Shampoo, you know why!