Soaps originated thousands of years ago. Roman legend has it that the first use of soap was found as a result of animal sacrifice. Animal fat and ash accumulated at ceremonial altars were washed into rivers by rain, where women were washing clothes, and they found that it made their clothes cleaner! Consequently, they started using “soap” in their baths as well. Today, soap is an umbrella term we use to describe substances that are used for cleaning.
However, in chemical terms, soap is made by a process called saponification, which is when a compound of natural oils or fats is treated with a strong alkaline solution like lye, soluble sodium or potassium hydroxide.
So how does soap clean? It emulsifies oil and water. A soap molecule has a head and a tail. The head is hydrophilic (water-loving) and the tail is lipophilic (oil-loving). So the tail sticks to surface oil and the head to water. When you wash your face/body, soap molecules will break free from the skin along with the oil (and dirt that comes with it), as you rinse it away with water.
Soap does its job too well at removing dirt and oils from our skin, it can remove too much of your skin’s natural oils and moisturizers and become a backlash on people who has sensitive skin or prone to dry skin. Plus, Soap is also very much an alkaline, ranging from pH 8-12, (if you’ve read our pH5.5 post you’ll already know this!) thus it disrupts the performance of your acid mantle, skin’s natural protective barrier.
To avoid soap, we can instead use other surfactants with lower pH values like Sodium Laureth Sulfate (SLES) which does the same job but is milder to your skin. SLES can be sourced from petroleum or naturally from coconut/palm oils. So why not choose plant-based ingredients that are safer for us!