Apple cider vinegar and Aztec Secret Indian Healing Clay are two budget-friendly, cult status beauty products that work beautifully together. Why are they such perfect partners? Well… it’s got something to do with the magic known as pH.
What is pH?
pH is a measure of acidity or alkalinity – the amount of hydrogen ions (H+) in something. It’s a log scale, which means something with a pH of 1 has 10 times the H+ of something with a pH of 2; something with a pH of 2 has 10 times the H+ content of something with a pH of 3, and so on. So if you dilute something with a pH of 3 by a factor of 2, you don’t end up with pH 6 (you actually end up with pH 3.3).
Apple cider vinegar (ACV)
Vinegar is produced from alcohol by acetic acid bacteria. These bacteria basically eat alcohol and poop out acetic acid, the chemical which gives vinegar its sour flavour and its low pH.
Apple cider vinegar, as you might’ve guessed, is acidic. The exact pH will vary a bit between brands, and between batches. The last inch of my Bragg’s Apple Cider Vinegar sits at about pH 3-4 (ACV is usually cited as pH 4-5, so mine is a tad stronger (possibly due to it continuing to ferment in the bottle – it’s been open for a fair few months).
Your skin is at around pH 5. While there are lots of skincare products with low pH – BHA treatments, for example, have to be at pH 3-4 to work – low pHs can irritate sensitive skin, and it’s a good idea to let it adjust slowly and use diluted mixtures of ACV. It’s also a good idea to spot test before using undiluted compresses of ACV to treat pimples – ACV’s low pH level can cause chemical burns and scarring.
Aztec Secret Indian Healing Clay
Passing over the awkwardly pre-PC product naming, Aztec Secret Indian Healing Clay is a green calcium bentonite clay and is probably one of the best value clays on the market – a 1 pound tub will set you back $6 on iHerb (and there are frequent discounts too – you can use my code NUD131 for 10% off on your first purchase, if you haven’t been sucked into the deep iHerb hole already, and it gives my more spending credit to sink further into the hole! Mutual enabling = the best kind of enabling).
I’m a bit weirded out by how the makers of the product seem to think “feeling your face pulsate” is the main selling point of this product, and I loathe having the word “impurity” in skincare marketing, but I love this product so much I’m willing to gloss over it.
The instructions specify mixing the clay with equal parts of raw apple cider vinegar or water. What happens in each case?
Mixing the clay mask
I placed 1 teaspoon of clay in each bowl, and added 1 teaspoon of water to the bowl on the left, and 1 teaspoon of ACV to the bowl on the right. You can already see a big difference – the puddle of water on the left looks like it’s keeping its distance from the clay, while the puddle on the right is happily mixing away.
Interestingly, adding apple cider vinegar to the clay made it immediately fizz like mad:
Fizzing like mad is a telltale sign of a chemical reaction – specifically, one that uses up the H+ ions that make acids acidic. We can check this with some handy pH paper:
Water with clay (lumpy mess on the left) has a pH of about 8, while ACV with clay (smooth paste on the right) has a pH at a much more skin-friendly, acid mantle-preserving 5.
(Pro tip: when measuring the pH of something that’s not going to interact well with pH paper, you can sprinkle a few drops of water on top, roll it around for a while to let the H+ ions diffuse into the water, then test the water on top. This works with things that will smear all over the paper like clay masks, as well as other things like oil-only creams which don’t really have any free H+ ions floating around, but will the moment it hits something watery like your skin.)
So there we have it – ACV straight from the bottle is likely to be too acidic (low pH) to slap straight on your skin, and Aztec Clay is too alkaline (high pH), but you can mix them to essentially cancel each other’s pHs to a happy middle ground. Additionally, they mix together so much smoother and save you a lot of hair-tearing lump-mashing. Happy masking!