DIY ‘No Poo’ shampoo problems (or, why pH matters)

A quick search on google will reveal multiple alternatives for ‘no poo’ hair cleansing. ‘No poo’ is a collective term for methods of washing hair without commercial shampoo, but is often used to describe the baking soda and apple cider vinegar method which is one of the most basic (and therefore popular when starting out with DIY products) methods. It also happens to be a perfect way to explain how pH affects your hair, so I will be using it.

But one step at a time, let’s make sure we understand pH first:


pH (potential of Hydrogen) is the measure that defines the acidity or alkalinity of a substance. pH is measured on a scale, between 0 and 14. A pH less than 7.0 is acidic, 7.0 is neutral, and a pH higher than 7.0 is alkaline.


Hair and skin are covered by a very thin layer called the mantle, which is comprised of oil, salt and water. It is moderately acidic and has a pH of between 4.5 – 5.0. This acidity prevents fungi and bacteria, and keeps the cuticle closed and healthy.

An inadequate hair product can disrupt the natural pH of the hair. If your hair care routine is too alkali your hair cuticles will stay open and your hair will become dry and brittle. But if you use pH balanced products (close to the natural pH of the hair), your hair cuticles will close properly which will result in healthy shiny hair.

However, this is not the full story, let’s take a closer look at the baking soda and vinegar method to understand


The basic standard for no poo is to simply wash with diluted baking soda, and then rinse with diluted apple cider vinegar (ACV). The idea behind using ACV after baking soda is referred to as pH balancing: the baking soda alkalizes and cleans, the ACV rebalances back to acidic and conditions. You’ll find a lot of opinions about this one, with a plethora of arguments both for and against it. I am going to stand on the ‘against’ side for this one, but not without giving you the reasons:

Baking soda has a pH of 9.5, i.e. very alkali in comparison to your mantel.
ACV has a pH of 3.0-4.0, i.e. slightly more acidic than your mantel.
From what I can gather, many people using this method understand that 9.5 is a hugely alkaline pH to be using on your body, but believe two things: 1. That diluting the baking soda reduces it’s pH significantly, and 2. that bringing hair back to it’s natural pH with the ACV fixes any problems the alkaline would present. I would like to clarify these misconceptions a little and explain what happens to your hair with this method.

1. Thanks to a few DIY hair product users who also test the science we now know that the pH of diluted baking soda doesn’t change much with dilution. It takes diluting 1 teaspoon with 10 cups of water, to affect the pH by just 0.5 bringing it to 9.0. If you add another 10 cups of water nothing changes. If you then take 1 teaspoon of this solution (of 1 teaspoon baking soda and 20 cups of water), and add that to a cup of water then the pH drops to 7.0, which although neutral, is still comparatively high alkaline in comparison with your pH 4.5 mantel.

2. Rinsing with ACV is definitely recommended if you’re going to use baking soda to wash. It does close the cuticles that the high alkali opened, and you don’t want to leave your hair open to environmental damage. Apple Cider Vinegar at pH of around 3.5 is only mildly more acidic than your 4.5 mantel. The vinegar is not the cause of the problem in this method, it does help prevent further damage, but ACV’s ability to smooth over the outside helps disguise the slow internal damage being done.

With these two pieces of information, it’s easy to see that the main problem lies with the baking soda. So let’s look a little closer at what it does. At a glance, baking soda opens the cuticles giving hair an extra good clean. Doesn’t seem so bad, but let’s look closer. Not only does it clean the dirt away, it also strips the natural oils essential for hair health. On even closer inspection we find out that the alkali is slowly dissolving the disulfide bonds between keratin protein molecules, which can eventually dissolve the protein completely. This happens gradually over time but eventually results in very damaged hair, presenting as dry, brittle, split ends, etc.

If you take away the science and go on ‘feel good’ factor, it’s very understandable why a lot of people love this method, for a while at least. Highly alkaline solutions such as baking soda make your hair soft and manageable, BUT, that is really the disulfide bonds in your internal hair structure being weakened by the alkaline. Overall, forcing your hair between high and low pH extremes makes it vulnerable, but the damage may not be noticeable till it’s too late.


While the baking soda and ACV method can be great for an occasional clarifier, and I’d actually recommend it for this, as a regular shampoo you really want to use products that stay close to your natural pH, and avoid these huge fluctuations.

There are other no poo methods that have similar problems, and yet, good uses. Take Castile for an example, the best thing about Castile is its multi-tasking property, you can use it for cleaning just about anything from your food to your pants to the floor. This makes it an ideal product for short term use when traveling, for example. However, if we go back to our pH scale, we find that Castile has a pH of around 8.0-9.5 so again, not recommend for daily use. Though I would like to point out that daily use is not really needed and I have used my own ‘liquid Castille‘ as the base for all my body cleaning products for years with fantastic results.

Still, so as not to leave you with problems without your choice of solutions, check out my next post for some great DIY, pH balanced, nourishing shampoos.


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