Foaming face cleanser with manuka and kumerahou

New Zealand has many native plants these have astonishing properties to heal, nourish and protect your skin. As with most natural botanicals, they work with your skin’s function rather than against, without the side effects of harsh, dangerous or damaging chemicals, to keep your skin’s protective moisture barrier intact. Did you know that over 80% of New Zealand’s plants are found nowhere else in the world? As I’m learning more about the natural wealth of our native plants, I’ll be including our native botanicals in some of my formulations, starting with this gentle foaming facial cleanser.

This foaming facial cleanser contains two star ingredients: manuka and kumerahou. Manuka is well-known for its antibacterial properties. It helps keep the skin clear and fight bacterial growth which can cause blemishes and breakouts. Kumerahou contains natural saponins, which gently and effectively cleanse without damaging the skin’s moisture barrier. Together they make for a mild cleanser which is suitable for all skin types, gentle enough for sensitive skin, yet effective to help combat acne and blemishes, without irritating the skin.

Did you know that 80% of New Zealand’s unique flora are found nowhere else in the world?

To create the foam, you need a special foaming bottle that pushes the cleanser through a nozzle where it is mixed with air to create foam. You can buy them from places where they sell cosmetic bottles and jars, like Arthur Holmes. I have also seen them at $2 shops and Storage Box, but you can also order them from AliExpress.

If you do not have a foaming bottle, but like the ingredients, check out this Manuka and Kumerahou Micellar Water – a very gentle cleansing water for your face.

All the ingredients I used to make this foaming face cleanser are available from Pure Nature, except for the preservative, which I got from The Sourcery.

Foaming face cleanser with NZ native botanicals

A gentle, natural foaming cleanser with manuka and kumerahou. Suitable for all skin types, but particularly for acne-prone or blemished skin due to its anti-microbial and anti-bacterial action. It is pH adjusted to the skin’s pH and contains hydrating and soothing ingredients to keep the skin’s moisture barrier intact.

INCI: Leptospermum Scoparium (Manuka) Leaf Water, Coco-Glucoside, Glycerine, Pomaderris Kumerahou (Kumerahou) Leaf & Flower Extract, Caprylhydroxamic Acid, Glyceryl Caprylate, Lactic Acid.


Manuka hydrosol: This is the foundation of the cleanser. Manuka hydrosol is a by-product from the manuka essential oil distillation. It is the water that is left over after the oil has been strained off, and it contains all the water-soluble goodness with the infusion of the manuka essential oils. Manuka has anti-bacterial, antioxidant, anti-inflammatory properties and the hydrosol makes for the perfect gentle cleanser base for this foaming cleanser

Kumerahou extract: Kumerahou has a high saponin content, a natural surfactant which produces foamy lather. In addition to its gentle cleansing action, kumerahou has also anti-microbial and soothing properties and is a great combination with the manuka.

Coco-glucoside: Derived from coconut and corn sugar, it is one of the mildest surfactants and often used in baby shampoos. Although I love my soaps, soap is the one product that you really should never use on your face.

Glycerine: This is a humectant, meaning it attracts moisture to the skin. I’m adding it to the cleanser because it helps reduce the drying out effect that you often get when using cleansers. The glycerin will keep your skin hydrated.

Preservative: Because this is a water-based product, you do need a preservative. For this product I’m using a natural preservative called Spectrastat G2. It contains a blend of caprylhydroxamic acid and glyceryl caprylate which effectively controls mould, bacteria, fungi and other nasties – things you don’t want in your products.

Lactic acid: This is something you should have in your inventory anyway. Lactic acid lowers the pH of your product. You need to do this for two reasons: 1) most natural preservatives only work within a narrow range of pH, and 2) to bring the pH of the product to match the pH of your skin – this helps prevent damaging the protective moisture barrier of your skin. Lactic acid is a natural ingredient, it occurs naturally in fruits, sugar cane and milk. It can also be produced by fermentation of glucose syrup from maize by using a bacterial strain. I use 80% lactic acid, which I buy from Pure Nature.

So now you know what each ingredient does, let’s get to making it.

Making your foaming face cleanser

Step ONE:

Weigh out the manuka hydrosol and glycerine together in a beaker. Give it a quick stir.

Step TWO:

Add the coco-glucoside and the kumerahou extract. Stir again, but gently so that you don’t create bubbles.


Test the pH using pH strips. You can buy these at pharmacies, brew supplies stores, or suppliers like Pure Nature.

Your pH will most likely be around 10. This is due to the coco-glucoside, which is a very mild surfactant, but like all surfactants has high pH. This is too high and we need to lower it.

Step FOUR:

Add 1 drop of lactic acid. Give the solution a good stir and then test again.

Step FIVE:

As you can see, the pH has now dropped to somewhere between 5 and 6, which is acceptable.

Add the preservative and give it one last stir.

Step SIX:

Fill your foaming bottle and give it a try!

How to use a foaming facial cleanser: Wet your face with warm water. Apply a 1-2 pumps of foam to your face in gentle circular motions, avoiding the eye area. Rinse off with warm water. Use twice daily before moisturising.

What happens if I don’t use the lactic acid?

Cleansing products to work effectively usually have a high pH, somewhere around 9-10.5. It needs to be this high to remove oils, fats and grease. However, this is exactly what we don’t want to do on our skin. We don’t want to break the protective moisture barrier. We want to clean our skin without removing the conditioning sebum that protects and keeps our skin supple. Our skin has a pH of around 5.5, so we reduce the pH of the foaming facial cleanser to this by adding natural lactic acid – one single drop is all that is needed! With the pH of the product the same as our skin, it can cleanse without damaging the protective moisture barrier of our skin.

I decided to check the pH after every ingredient I added to see how the pH changes and also which ingredient is causing the high pH. Turns out it is the coco-glucoside that raises the pH.

The other very important reason for reducing the pH of your products is that most natural preservatives will only function within a certain pH range, usually somewhere between 4 and 7. If your product is outside this range, your product WILL NOT BE PRESERVED and you run the risk of your product getting mould, bacteria, fungi and all sorts of nasties. Always check with your supplier under what conditions and what pH range your preservative will work. My usual preservative Microcare DB only works if the pH is below 6. My other preservative Geogard Ultra works between 4-8, but it requires heating, which I wanted to avoid. So I’m using a new preservative called Spectrastat G2, which also works with a pH between 4-8. This is a new type of natural preservative, which you can get from The Sourcery.

The solution on the left contains lactic acid and the one on the right doesn’t. You can see that the lactic acid has also lightened the colour.

If you want to learn how to formulate your own skin care products, sign up for the FREE Masterclass by Formula Botanica*. This is the accredited school that I am studying with.

*Affiliated link


Makes 50 g. You will also need one 50 ml foaming bottle. If you are using a larger bottle, just double the amount or adjust accordingly using the percentages.

StageIngredient Category%g
AManuka hydrosolFoundation8743.5
AGlycerineFunctional – humectant42
BCoco-glucosideFunctional – surfactant52.5
BKumerahou extractBotanical extract – surfactant31.5
CSpectrastat G2Additive – preservative10.5
80% lactic acidpH adjuster
Please note all the ingredients are weighed not measured in volume


  1. Mix the ingredients from stage A together.
  2. Add ingredients from stage B, and stir gently, without creating bubbles.
  3. Use a pH strip to check your pH. It should be within the range for the preservative you are using.
  4. Lower the pH by adding ONE DROP of lactic acid.
  5. Check the pH again. It should now be within the acceptable range, otherwise add another drop and check again.
  6. Add the preservative and stir.
  7. Pour in foaming bottle.

As with any skin care product, it is best stored and kept out of direct sunlight and not exposed extreme heat, which will degrade the beneficial compounds and reduce the effectiveness of the product. With correct preservation, it will keep for 12 months.

If you enjoyed this article, please consider donating a coffee, or a flat white as we call it here in New Zealand! This website is only possible due to my coffee consumption and early morning starts.

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