Yaso Shan tells us the story of how soap began, are you sitting comfortably? Then we’ll begin…
In the world of personal hygiene, getting clean is big business. From shower gels to cleansing bars and from face washes to body scrubs to name but a few. But what about our old faithful: the humble bar of soap? It seems to be enjoying a bit of resurgence not only in the personal hygiene products market but also in the eco-friendly products market. The latter is mainly because traditional soap does not involve unnecessary packaging or bottling, least of all in the use of plastic such as liquid soaps, and being biodegradable, waste is not a problem. This sits well with many consumers worried about plastic pollution and excessive production of non-recyclable waste. Moreover, the seemingly endless varieties on a tried and tested basic soap formula provide much choice to consumers. So how and where did it all start for soap?
The precise nature in which soap came to be discovered is somewhat unclear and there are various legends surrounding its beginnings. The following timeline gives a broad indication of how it all started and how it progressed to the product we have come to enjoy as the modern soap. Much of it remains unsubstantiated, mainly because it is based on myth and legend, some facts we may never know about as there are no written records from some parts of the world as well as gaps in historical records due to missing evidence. Nevertheless, a broad picture emerges of the history of soap:
History of cleansing in India and China
Before the advent of soap, the primary cleansing agent in ancient India was taken from soap nuts also known as soap berries (from the plant Sapindus saponaria). The literal translation of Sapindus is sap = soap and indus = India. In other words, soap from India!
The nut was used in ancient China as well and its usage spread from India to Middle Asia and then Europe. Soap nuts are boiled to soften them up, and then crushed to filter out the essence which contains the all-important cleansing chemicals. It lathers but in small quantities. Ancient India also used shikai or shikakai (a variant of the acacia plant) as a hair and body cleanser.
The skincare routines of ancient Indians involved the addition of a variety of herbs such as turmeric, tulsi (holy basil), neem (bark and leaves), lotus petals and sandalwood paste amongst others which were common ingredients in their skincare creams.
There is evidence that soaps were made and used in ancient China as far back as 1300AD. A bronze vat was found with traces of what could be soap material although its purpose was unclear (ie. was it for personal use of for manufacturing?). As early as 3000 years ago during the Zhou Dynasty, the Chinese discovered that using ashes of certain plants could be used to remove grease, a method improved upon in subsequent dynasties using and mixing these ashes with crushed sea shells, as well as discovering a naturally-occurring form of saponin which was a useful and effective cleaning agent.
Modern day soaps-making practices
Modern soaps benefit enormously from the industrial process, our advanced understanding of the chemistry of soap and an array of ingredients from around the world on the back of a global trading history. Technological revolutions enabled a number of synthetic formulations which resulted in modern detergents with superior cleaning power. Much of the developments around 1940s to the present day was centred around keeping costs low as soap-making was rather an expensive process. Laundry soap was replaced by superior washing powders, and then biological varieties using enzymes. Products such as dishwashing detergents, fabric softeners, disposable cleansing wipes and antibacterial hand washes including eco-friendly, biodegradable detergents to name but a few were all entering the market.
However, many people still use the cost of the commercially mass produced vegetable soap as the yardstick by which to judge soaps today even though they are not necessarily better. Handmade, natural, organic and botanical soaps are fast-becoming very popular in keeping with changing times, fashions, tastes and sensibilities relating to environmental concerns, a desire for biodegradable products as well as their beliefs and principles about the use of animals in personal hygiene or grooming products.
Historically, the fat component of the very early soaps was from animals as harvesting and processing of fats from vegetable sources were not discovered as yet. Notably, these fats tended to be tallow from the carcasses of animals ie. fat from rendered beef, and there are very compelling reasons for using this. Unlike vegetable oils that are unstable at high temperatures and oxidise easily, releasing free radicals that contribute to the breakdown of cells and tissues in our bodies, beef tallow is stable at high temperatures (400F/2500C), making it safer and more reliable for use in many products. Its stability is such that it is even used in the new £5.00 polymer note! Vegetable-based tallow can be made from coconut or palm oil by treating the oil with water at high temperatures which hydrogenates the triglycerides in them to stearic acid. However, plant-based stearic acid is more expensive than animal-based tallow but may sit more comfortably with vegetarians and vegans.
Legend has it that the use of animal fat originated from a group of Roman women who were washing their clothes in the River Tiber located at the base of Sapo Hill in Rome where women used to congregate when washing their clothes. They soon discovered that when the animal fats from ritual sacrifices ran down the hill to the river below, it created a soapy clay mixture which when used to clean their clothes became much easier to do when this cleansing substance was used. However, this is disputed by the great natural historian Pliny the Elder who credited the invention of soap to the Gallic and Germanic tribes that the Romans encountered during their conquests. Regardless, what is definitely known is that the Romans were using soap in their baths by 200AD.
The chemistry of soap
The Sumerians (approx. 3000BC) used a slurry of ashes and water to remove grease from raw wool and cloth so that it could be dyed. Ashes were referred to as ‘al-qualy’ and modern chemistry uses the word ‘alkali’ which is derived from this original word. Modern analytical methods have shown that ashes have a high alkali content which is one of the basic ingredients of soap-making.
The priests and temple attendants of this time used the solution from ashes to purify themselves before sacred rites and noticed that adding a little grease improved the performance of the alkali. They refined the process by directly boiling fats and oils in the alkali before using it for cleansing.
Modern chemistry has made the understanding of the process of soap-making much clearer. Essentially, the production of soap entails a chemical reaction involving the saponification of fats by an alkali such as sodium hydroxide (traditionally, this was lye, originating from the Old English word léag, meaning ‘to wash’ or ‘to lather’). The reaction releases glycerine (or glycerol) which can remain in the soap to varying extents as a softening agent but some manufacturers separate it from the final product. The type of alkali and fats used determines the type of soap yielding any number of combinations on formulation and creating the many wonderful varieties that are on the market today.
Even before soap started to make an appearance, early civilisation looked to nature. The soapwort plant (Saponaria officinalis) was mixed and agitated with water giving rise to the first natural soap. Modern interest or resurgence in natural skincare products has led to soap-making using only plant fats and plant-based alkalis and using only natural fragrances such as essential oils to add fragrance to the final product.
Advances in modern soap-making as well as our understanding of the chemistry of soap ingredients has also enabled superior products that are now refined for different purposes. Soap in the mid-19th Century became a separate commodity from laundry soap which we now refer to as household detergents (modern petroleum-based detergents cannot, by law, be called soap). Laundry soaps were far too strong and drying to be used on the skin but were more suited to cleaning hard surfaces and clothes. Advances in technology and chemistry has enabled variations of soaps such as liquid soaps and shower gels, the latter which were invented in the 1970s to enter the market and which have now become the mainstay for most households.
Liquid soaps however, first made their appearance as early as the mid-1800s (probably not in their current form) and in 1865, William Shepphard patented liquid soap. Its instant popularity was further enhanced by the creation of Palmolive Soap in 1898 by B.J. Johnson.
Shower gels are of a different chemical composition to liquid soaps in that they do not contain saponified oil. Commercial scale shower gels use petroleum-based ingredients formulated to have a greater foaming capacity with numerous chemicals added to help cleanse the skin better, to lather better in hard water areas and to not leave mineral residues on the skin or shower/bathtub. They are also pH balanced so they are unlikely to irritate the skin. However, many shower gels can still dry the skin so manufacturers tend to include various moisturisers to mitigate this unwanted effect. Many modern shower gels also have conditioning agents which makes them versatile for cleaning both hair and body.
Some of the early developments in soap-making have survived to the modern age and three such examples are the Aleppo Soap, Castile Soap and the African Black Soap. They deserve a special mention and in the context of the soaring popularity of natural skincare, it is easy to see why.
Aleppo soap is considered one of the purest soaps as it is made with all natural ingredients. It originated from the Syrian city of Aleppo, a place brought to our attention in current times due to the civil war raging there. Aleppo soap does not dry out the skin, it also moisturises and nourishes the skin and is purported to benefit a host of skin problems such as eczema, skin breakouts, inflammatory skin conditions, insect bites and skin infections. However, the exact origin of the soap is lost in time with the earliest written record dating as far back as the 8th Century AD. After the Crusades, European nations adopted Aleppo soap and started producing their own variations. However, the ancient city of Aleppo thrived on trade for thousands of years, famous for being the endpoint of the illustrious Silk Road trade route that bridged the East and the West.
Generations of merchant families and manufacturers made the unique soap for thousands of years and the formulation has remained surprisingly unchanged in all this time retaining its original form. Olive oil, sweet bay (laurel) oil and water are mixed with the alkali sodium hydroxide, heated and then left to cool. After cutting, it is left to age in the shade for a minimum of seven months, during which time it will change colour from green to its trademark brown and giving its distinctive aroma. Of course, bay (Laurus nobilis) has remarkable antibacterial and antifungal properties, and could explain some of the benefits of this soap in conditions such as acne, insect bites and skin infections.
Castile soap originated from variations to the Aleppo soap when Europeans trading in Asia, the Middle East and Persia used close variations of its ingredients since the original ingredients were not available in Europe at the time. Revolution to public sanitation and personal hygiene was sorely needed in the Middle Ages (there was rampant spread of various diseases) and with the arrival of Muslim soap makers to Spain and Italy in the 12th Century, the first European soap took hold. Soap export centres were dominated by major Spanish and Italian cities. The superiority of the Castile Soap (named after the Castile region of what is now modern Spain) enabled it to be more distinguishable from all its contemporaries at the time, establishing its popularity so much so that it continues to this day. Castile’s easy access to olive oil made the soap mild and effective but also enabled the creation of a pure, white soap as it aged, making it very popular with the Spanish royalty as well as other royal houses across Europe.
African Black Soap
Meanwhile, in another part of the world, the African Black Soap which originated in West Africa also retains its popularity to this day. Invariably a fairtrade product, the soap is usually made by women and the traditional recipes were (and continue to be) handed down through the generations with variations to the original recipe. It is also referred to as anago, alata, simena and dudu-osun soaps with basic ingredients of burnt ash from local plants that are harvested giving the soap its characteristic black colour.
Local plant are used for burning as the alkali is sourced from locally derived cocoa or palm tree and sometime shea tree bark or plantain skins are used instead. The ash from the burnt plant provides the alkali and the fat content is usually from shea butter, palm oil or coconut oil. There are many benefits of this soap from problem skins to providing excellent UV protection (because of the high level of shea butter). However, it is not ideal for those with caffeine sensitivity and practical issues such as its rapid absorption of water due to its high glycerine content means it can break away or melt easily so it needs to be stored in a bag or covered soap dish away from water.
It is safe to say that soap-making has enjoyed a very long tradition dating as far back as the pre-Babylonian times. A combination of serendipitous discoveries, high levels of skill, ingenuity and dedication of the many craftsmen and women over the years has led us to have the variety and choice of soaps we enjoy to this very day; a luxury for which we should all be grateful perhaps?
Yaso Shan is a registered member of the College of Practitioners of Phytotherapy (CPP), a leading UK professional body for qualified and practising members of western herbal medicine who began her career as a Lecturer in the Health Sciences, specialising in the biomedical sciences, physiology, pathology, infection and the principles governing conventional medical treatments. Her interest is in natural therapies, particularly plant remedies, stems from her own cultural perspective together with the fundamental belief that enabling the body to heal itself lies at the heart of all effective therapies. She is also a member of the Royal Society of Biology (RSB)
Medical Writer, Health Consultant & Lecturer