Why use ACV to cleanse?
The main element in vinegar is acetic acid, which can kill bacteria and prevent it from multiplying. Vinegar is a natural preservative and disinfectant, so is this why curlies are using this on their hair?
According to scientific consultant and NASA Educator Yolanda Anderson, “ACV (chemically known as acetic acid with a pH of around 3) is an acid substance that lowers the pH of hair. This makes cuticles lie flat, thus increasing the amount of shine."
What does pH have to do with hair?
If you need a refresher course on pH, our contributor Charlene Walton explains that "substances with a pH between 0 and 6.9 are acidic, 7 is neutral, while substances between 7.1 and 14 are alkaline. For example, relaxers rank higher on the scale with a pH normally around 13, pure water is neutral at 7, and apple cider vinegar (undiluted) is on the opposite side of the scale around 3. A higher pH substance or product on the scale opens the cuticle and lower pH closes the cuticle."
While ACV may successfully make your hair appear shinier or smoother initially, Anderson says "ACV will make hair dry and brittle stripping it of its’ natural oils even though initially providing extra shine.”
But does it work?
It depends, are you aiming to cleanse your hair or your scalp? As Dr. Kari Williams explains, the acetic acid in ACV "is a potent antimicrobial that can kill some types of bacteria," making it an effective "homeopathic way of removing buildup and dead skin cells from the scalp." A healthy scalp is crucial to growing healthy hair and avoiding common irritations such as flakes and bacteria.
In regards to cleansing the hair (not scalp), JC from The Natural Haven conducted an experiment in which she took close up images of the strands before and after washing them with shampoo, apple cider vinegar and baking soda. While shampoo did effectively remove oil from the strands, apple cider vinegar and baking soda both left a significant amount of oil on the strands. You can see the photos of her experiment here.
In summary, while ACV will effectively cleanse your scalp, it can leave your hair dry, brittle and dirty.
Why use baking soda to cleanse?
The official name for baking soda is sodium bicarbonate and it works wonders in the fridge and freezer for removing funny odors. It has also been used as a toothpaste substitute and is commonly used in cooking. Anderson explains that, “baking soda is just as harsh on the hair. It has a pH of 9, which is more basic than water. Baking soda is a known alkaline irritant (on the other side of the pH scale). Alkaline shampoos strip the hair’s natural oils and disrupt the acid mantle, causing the hair to become dry leading to porous, fragile hair.”
Many curlies have turned to baking soda for clarifying their hair, but because baking soda has a pH of 9. The key to using baking soda without damaging your hair is to be sure to normalize the pH level by using a low pH level product afterwards, for example a diluted ACV rinse.
Read more: Pros and Cons of Baking Soda as Shampoo
The bottom line
According to Anderson, they both damage the hair in the same manner. Chemically speaking it, they may not be so great for our curls and coils, and while other ingredients may soften the blow, they can damage the hair to a degree. A safer way to use them is to use products that have those ingredients in their formulas, like SheaMoisture Jamaican Black Castor Oil Strengthen, Grow & Restore Shampoo (I love this shampoo by the way!), which contain ACV, or Pureology Purify Shampoo for color-treated hair, which has baking soda. Another option is to add some of these ingredients to your current shampoo to provide that extra oomph without allowing it to damage your strands.