There is something gratifying about releasing a large slab of soap from its mold, still warm to the touch, the fragrance of its essential oils filling the room. Soap that is made by hand is a world apart from mass-produced soap, usually made using palm oil (read about the environmental disaster that is palm oil here ) and sometimes animal fat. Petroleum derivatives are a common ingredient of mass-produced soap as are a variety of other synthetic ingredients including synthetic fragrances, synthetic preservatives, antibacterials such as triclosan which is a known hormone disrupter, and EDTA (ethylenediaminetetraaceticacid), a heavy metal chelator which can mobilise heavy metals in our waterways.
In addition to containing suspect ingredients, mass-produced soaps are often very drying to the skin, since they are frequently stripped of the moisturising glycerol found in natural soap, and may not be ‘superfatted’, which means they contain little free oil to moisturise the skin. Mass-produced soaps are also low on the valuable ‘unsaponifiable’ component, so-called because it is the fraction in oils which cannot be turned into soap. The unsaponifiable fraction contains most of the vitamin and phytonutrient components of the oil, which are nourishing to the skin when included in both soap and moisturisers. The unsaponifiable fraction is largely removed from refined oils: for example, unrefined shea butter may contain between 6-17% unsaponifiables, whereas refined shea butter typically contains less than 1%. Natural soap made using unrefined organic oils and formulated so that it is superfatted, will be rich in moisturising natural glycerol and nourishing unsaponifiables. This soap will gently clean the skin without stripping its natural oils. Here we attempt to explain in simple terms the chemistry behind real soap, and why we think our certified organic soap is amongst the purest you can buy, and is best for your skin.
How exactly do you make soap?
Soap is made using a classic acid-base chemical reaction, resulting in the formation of a salt, which is soap. Yes, soap is technically a salt! The acid part is provided by the weak organic fatty acids that make up vegetable oils (and animal fat). The base or alkaline component is known in soap-making terms as ‘lye’. Lye may be made using sodium hydroxide (NaOH) to produce solid soap, or potassium hydroxide (KOH) to make liquid soap. The fatty acids in vegetable oils and animal fats exist mostly in the form of triglycerides, which are composed of a glycerol molecule bound to 3 fatty acid molecules. A molecule of glycerol is released as part of the acid-base reaction when the fatty acids react with the lye.
Lye + triglyceride = soap+ glycerol
Base + acid = salt + glycerol
This chemical reaction is called ‘saponification’, which means ‘the process of turning fatty acids into soap.’ Heat is released as part of the process – that’s why a freshly made slab of soap is warm. In mass-produced soaps, the valuable glycerol fraction is removed from the mixture and used in other skin care formulations like moisturisers, as well as in the food and pharmaceutical industries, which is one of the reasons mass-produced soap is so drying.
Isn’t lye harmful to the skin?
Lye is a strong alkaline solution that will ‘burn’ the skin on contact. The beauty of the soap-making reaction is that when performed correctly, all the lye is consumed in the process, so that there are no remaining free lye molecules in the soap. The product is the stable salt which is soap. So yes – lye is harmful to the skin, but a correctly made soap does not contain lye. In fact, most handmade soap will contain an excess of oil which ensures that all the lye is consumed, and 'superfats' the soap, providing additional moisturising properties.
The process - solid soap
Handmade bar soaps can be made using either the ‘cold process’ or ‘hot process’ method. Both methods allow retention of most of the beneficial components of the oils. In cold process soap-making, the process we use at Mokosh to make bar soap, the lye solution is prepared by adding a predetermined amount of sodium hydroxide to distilled water. When the lye solution has cooled, it is added to oils and butters which have been heated to between 40-50°C . The two are blended using a whisk or electric stick blender until the mixture thickens. At this point essential oils and plant extracts may be added. The mixture is then poured into moulds and covered in blankets for insulation, and left undisturbed overnight to allow the saponification reaction to proceed. The next day, the soap is solid but still warm, and ready to be cut into bars. At this point, the soap is quite soft, similar in consistency to cheddar cheese. The bars are then cured for a minimum of 4 weeks, which allows excess water to evaporate, which makes the bars firm and adds to their quality.
It is possible to make bar soap without true soap as an ingredient, using synthetic detergents instead - these are 'non soap' bars some people use instead of true soap. However, most mass-produced bar soaps are made using the same oil-lye reaction used in natural soap-making. Following saponification, the mixture is boiled in water to remove the glycerol fraction, which is used in other products, after which the soap is solidified by adding salt (sodium chloride). The soap is then vacuum-dried to form pellets which may be blended with a variety of ingredients, usually synthetic detergents, fragrances, plasticisers and other compounds. The mixture is then homogenised in a process called ‘milling’ which is essentially pressing the soap through rollers. You may have seen ‘triple milled’ soaps which have undergone this milling process, which simply means the soap has been ‘well mixed’. The resulting mixture is then extruded and stamped in a soap press.
We love our soaps! They are luxurious to use, lather beautifully and those containing essential oils make you and your bathroom smell beautiful. Although most people don’t like the thought of using soap on their face, many of our customers find them so gentle, they can happily do so. Equally, many eczema sufferers find they can use our bar soaps, whereas standard soaps dry out their skin, resulting in eczema outbreaks. Our 100% certified organic Organic Olive Oil Soap (fragrance free) is particularly mild, being extremely high in glycerol. It seems that 100% olive oil soaps are the gentlest, because they result in the release of the most glycerol. Glycerol is a humectant, which means it attracts water, and therefore draws water to the skin, rather than drying it out. Our certified organic Coconut & Cacao Butter Soaps in Sandalwood and Rose geranium are also extremely mild, glycerol-rich, and high in nourishing unsaponifiables. Because they contain coconut oil they form a richer, creamier lather than our pure olive oil soap.
Because all our bar soaps are naturally rich in glycerol, they need to be stored on a soap rack to dry between uses, so that they do not absorb water and go soft. When looked after, one bar will generally last around 4 weeks when used by one person.
Palm oil is found in most soap
If you pick up any bar soap in a supermarket aisle, health food store or organic store and look at the ingredients list, you will likely see the words ‘sodium palmate’ and ‘sodium palm kernelate’ near the top. These are the terms for palm oil and palm kernel oil that have undergone the saponification reaction. Currently, Indonesia and Malaysia are burning rainforest at an alarming rate to clear land for palm oil plantations. Palm oil is a multi-billion dollar industry resulting in the destruction of rainforest to satisfy our demand for cheap vegetable oil in our soap, skin care products (read more here) shampoos and conditioner (read more here), and the majority of packaged foods. These forest fires cause massive pollution problems and release billions of tons of carbon into the atmosphere. Deforestation is likely to result in the extinction of the endangered orang-utan and Sumatran tiger and numerous other lesser known species, and is causing a humanitarian crisis in displaced indigenous populations. Please do not buy products that contain palm oil!