Natural Soap pH Balance : The Science of pH Explained

Brace yourself, some basic understanding of what is exactly pH is coming

In the world of skincare, "pH-neutral" is the ultimate golden buzzword. As I craft my soaps in my Berlin studio, I see the confusion it causes: Is natural soap "bad" because it's alkaline? Or is that "neutral" bar just a synthetic detergent in disguise? Whether you are shopping in Prenzlauer Berg or ordering from across Germany, understanding the chemistry of your skin is the first step to a healthy routine.

Brands use terms like "pH-neutral" or "pH-balanced" to imply superior safety. But here is the secret: due to a lack of standardized regulations, companies can use these terms quite freely to make a product seem more desirable. While a prominent pH claim is a powerful marketing tool, the truth is simpler: if a skincare product were genuinely unsafe, it would not be legally available on the market. The real question for you isn't just about basic safety, it’s about compatibility with your specific skin type.

We all have different skin types, and different logics apply to our cosmetic routines. Factors like genetics, gender, age, and even local environmental conditions play a role. Therefore, the remarkable results a product achieves on one person's skin do not guarantee the same outcome for another. For instance, natural soaps may not be suitable for everyone, especially when used on the face. Consequently, before incorporating any new product into your routine, it is advisable to conduct a patch test on a small area of skin to assess its compatibility.

We all have different skin types : different logics then apply in term of cosmetic routine

However, individuals have varying skin characteristics, including genetics, gender, age, skin type, moisture levels, and anatomical conditions. Therefore, the remarkable results a product may achieve on one person's skin do not guarantee the same outcome for another.

For instance, natural soaps may not be suitable for everyone, especially when used on the face. Consequently, before incorporating a new product into your skincare routine, it is advisable to conduct a patch test on a small area of skin to assess its compatibility before applying it more broadly.

Understanding Natural Soap pH Balance

pH (Potential Hydrogen) indicates how acidic or alkaline a solution is on a scale of 1 to 14:

• pH 4.5 – 6.0: The slightly acidic range of healthy human skin.

• pH 7.0: Pure water (Neutral).

• pH 8.5 – 9.5: The typical range for natural artisan soap

Some common products of our everyday life and their pH

The 10x Rule: The pH scale is logarithmic, not linear. This means a jump of 1 unit represents a 10-fold increase. For example, lemon juice (pH 2) is 10 times more acidic than soda (pH 3). The further a product's pH is from your skin's natural level, the harder your skin has to work to rebuild its protective 'acid mantle.

The greater the difference between the skin's pH and the pH of the product you are using, the more efficiently the protective mantle is removed and the longer it takes the skin to fully rebuild it. An important factor here is time.

The pH of natural soap (in water) is slightly alkaline, and only in this state can the soap molecules do their job effectively. Since it is a rinse-off product, the contact between soap and skin rarely lasts longer than 30 seconds.

Practical example

When you shower or wash your hands with natural soaps, you come into contact with foam that is a mixture of water pH=7.5 (> 95%) and soap salts pH=9.5 (< 5%) and includes a large amount of air. The more extreme the pH of a substance is (far from 7), the more it will affect the pH of the mixture in which it is included. Keeping this following idea in mind and sparing you some calculations. The foam pH of babassu natural soaps is usually between 8.2 and 8.5.

Two different pH papers used: one showing between 8 and 9, and another more precise one gives an estimation close to pH=8.2

What is the acid mantle?

We can't talk about pH without the acid mantle, a protective film of sebum (oils), sweat, and amino acids. This acidity inhibits the growth of pathogens. When you wash, this mantle is temporarily stripped away. For most people, the skin is incredibly resilient and normalizes its pH within about 90 minutes. Natural soap is a 'rinse-off' product; it only touches your skin for about 30 seconds, giving your skin a clean slate to regenerate its natural defenses.

How to use natural soap to clean my face?

While using natural soaps for the hands or body is suitable for everyone (lucky you!), facial skin is more sensitive. Before following the advice in this section, please check that you have done your initial exercise: always try on a small area of your face first before more general application. If, like me, you pass the multi-day test with natural soaps on your face, congratulations! If not, please do not change your current habits. ​ The method you use to clean your face is of course a personal preference, but a few tips can not hurt :) Warm (not hot) water helps to open the pores slightly, while cold water tightens them.

Be happy, be soapy

1. Lathering by hand

We recommend it for sensitive facial skin. Use warm (not hot) water to create a generous lather in your hands.

• Gently massage the foam over your face with your fingers in circular motions.

• Rinse with cool water and pat dry to leave some water on your pretty face.

​ 2. Washcloth (soft fibers only)

This method has a light scrubbing effect, helping to remove dead cells. Excessive exfoliation or scrubbing will cause the skin to become red and irritated. If you are prone to acne, better use a clean washcloth every time.

• Rub the bar of soap on a clean, warm-damp and clean washcloth until a generous lather is formed.

• Apply it to your face with gentle circular motions.

• Rinse with cold water and pat dry

For both methods, and especially for dry skin, apply a moisturizer after washing the face.

A note for our Berlin neighbors: Since Berlin/Munich have notoriously hard water, the pH of your rinse water can affect how the soap feels. We recommend a quick cold rinse to help the acid mantle snap back even faster.

Sources

• ​Ronni Wolf, Lawrence Charles Parish, Effect of soaps and detergents on epidermal barrier function, Clinics in Dermatology, Volume 30, Issue 3, 2012, Pages 297-300

• Takagi Y, Kaneda K, Miyaki M, Matsuo K, Kawada H, Hosokawa H. The long-term use of soap does not affect the pH-maintenance mechanism of human skin. Skin Res Technol. 2015 May;21(2):144-8. Epub 2014

• Christine N. Duncan, Thomas V. Riley, Kerry C. Carson, Charley A. Budgeon, Joanne Siffleet. The effect of an acidic cleanser versus soap on the skin pH and micro-flora of adult patients: A non-randomized two-group crossover study in an intensive care unit, Intensive and Critical Care Nursing. Volume 29, Issue 5, 2013, Pages 291-296

• Baranda, L, et al. Correlation between pH and irritant effect of cleansers marketed for dry skin. International Journal of Dermatology. 2002, vol 41, pg 494–499.

• Mirela Moldovan and Alina Nanu. “Influence Of Cleansing Product Type On Several Skin Parameters After Single Use.” Farmacia, 2010, Vol. 58, 1

• Takagi, Y., et. al. [2014], "The Long-Term Use of Soap Does Not Affect the pH-Maintenance Mechanism of Human Skin" in Skin Research and Technology