The history of soap is long and fascinating. Soap has been made and used for thousands of years in various forms and by various people and much has been written about them all. However, it was really only from the 1800s onwards, as people began to understand the link between cleanliness and health, that the production of soap took off. Nowadays, washing with soap is commonly considered an indispensable part of basic hygiene.
Soap is a product of the reaction that takes place when an oil or fat meets an alkaline substance. Fat particles consist of three fatty acid molecules attached to one molecule of glyrcerin. When an alkali joins in and water is added, the bond is broken in a process called saponification. The freed up fatty acids go off with the alkali to form soap, leaving the glycerin behind. Soap is useful because it tends to surround fat particles and allow them to become dispersed in water, making them easy to wash away. Because of this tendency, soap has also been accused of stripping the skin of its own important natural oil, sebum. This is clearly a problem as the skin either dries out, and / or becomes oilier as it tries to compensate. It is, however, what makes soap so good at cleaning, as dirt is often trapped in fatty deposits. As fat is normally insoluble in water, grease and dirt can remain largely unaffected by washing with plain water. Soap solves this problem.
This same process is a fundamental part of what makes alkaline substances such as bicarb (baking soda) and washing soda so good at cleaning. As they come across fats, they begin to digest them, converting them into a crude form of soap and allowing them to be washed away. This is why touching an alkali makes your skin feel slippery – it is forming soap with the oil of your skin. Touching a very strong alkali is a very bad idea as this reaction can be so intense that the tissues begin to break down. To make soap, extremely strong alkalis such as lye (casutic soda) are used. These highly dangerous substances, along with whatever fat or oil is used, are transformed into usable soap and are no longer present once the process of saponification is complete.
I have several reasons for preferring to use a mild alkali such as bicarb (baking soda) rather than a soap for many cleaning tasks, but the fact remains that soap is very good at its job, and for some tasks it reigns supreme. There are some truly wonderful handmade soaps that use high quality plant oils, retain the softening glycerin, and sometimes add other beneficial ingredients.
Unfortunately, there are far more cheap and nasty soaps out there than wonderful, high quality ones. The problems with them are several. Firstly, they are normally made using animal fat, or tallow. This in itself is not necessarily a problem; some small-scale farms use fat from their animals to make lovely soaps. But mostly the fat is a by-product of the mainstream meat industry, an ugly world of animal misery and environmental degradation. As animals are fed on unnatural diets, kept in confined conditions and doctored with antibiotics and synthetic hormones, they tend to accumulate far more fat in their tissues than is healthy, or than consumers want to eat. Furthermore, toxins tend to accumulate specifically in these fat deposits. The result is that the floors of abattoirs and meat packing plants are literally littered with toxic, unwanted fat. Rendering this fat into tallow and selling it off to the soap-making industry goes a long way toward getting rid of this messy dilemma, and keeps the machine turning. It is ironic that the substance we use to keep clean and germ-free comes from the disgusting debris of one of our ugliest industries.
I think I will leave it there for now. More on this topic later, as there are many more angles to discuss and the subject of soap is a complex one. But next time you reach for a cheap bar of soap off the supermarket shelf… perhaps consider whether it may be worth looking for a cleaner option.