How Soap is Made, Its Uses, and Vegetable Fats Soap?
Soap is mainly used for washing, bathing, and cleaning, but soaps are also the important content of lubricants. Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution. In simple language the fats contain triglycerides and glycerol. The alkaline solution, often it can be LYE, promotes a chemical reaction when added to fats known as saponification. In saponification, fats are broken down yielding crude soap. Fats are transformed into salts of fatty acids and glycerol is liberated, leaving glycerin as a by product. By this we know the making of glycerin also. Glycerin has many uses, the most known to make tears by application on the eye during acting, using as a lotion on chapped skin to make it soft etc. So in lubrication greases soap is there. That is why we can use soap to remove bangles from the hand, ring from the finger etc by applying soapy water on the area.

How does the soap function?
We know by rubbing soap on our body with a little water a lather is formed and dirt is washed of. How does it occur? Normally the dirt does not dissolve in water. But dirt dissolves in the lather. As such the color of lather changes from pure white to grey depends on the amount of dirt. That is why, on a hot summer day though bath without soap is cooling, but after some time dirt comes out from the boy as tiny granules if we roll our hand over the body if the soap is not applied to the body, hence the essentiality of soap. When used for cleaning, soap serves as a surfactant in conjunction with water - the cleaning action of this mixture (it is slightly a complicated chemical process to understand easily).

Effect of Alkali (opposite of acid is alkali
The nature of the soap depends on the alkali material. Sodium soaps, prepared from sodium hydroxide, are firmer. Potassium soaps, derived from potassium hydroxide, are softer or liquid. Historically, potassium hydroxide was extracted from wood ashes. Lithium soaps also tend to be harder - these are used exclusively in greases.

Fats and Oils Used in Making Soap
Soaps are derivatives of fatty acids. Traditionally soaps are derived from triglycerides (vegetable and animal fats). Triglyceride is the technical name for these triesters of fatty acids. Typical vegetable oils used in soap making are palm oil, olive oil etc where the product is typically softer. Aside from olive oil, fats include coconut, palm, cocoa butter, hemp oil, and shear butter to provide different qualities. For example, olive oil provides mildness in soap. Coconut oil provides lots of lather. Coconut combined with palm oil provides hardness. Most common, though, is a combination of coconut, palm, and olive oils. Some fatty acids and oils are added for other benefits of the soap. For example to give different smells of sandal wood, Tulsi or ramachham etc.

History of Soap
The earliest recorded evidence of the production of soap-like materials dates back to around 2800 BC in ancient Babylon. A formula for soap consisting of water, alkali, and cassia oil was written on a Babylonian clay tablet around 2200 BC.

The Ebers papyrus (Egypt, 1550 BC) indicates that ancient Egyptians bathed regularly and combined animal and vegetable oils with alkaline salts to create a soap-like substance. Egyptian documents mention that a soap-like substance was used in the preparation of wool for weaving. A popular belief encountered in some places claims that soap takes its name from a supposed "Mount Sapo", where animal sacrifices were supposed to take place - tallow from these sacrifices would then have mixed with ashes from fires associated with these sacrifices, and water and convert to soap; but there is no such place as a Mount Sapo, and no evidence for the apocryphal story.

In France, by the second half of the 15th century the semi-industrialized professional manufacture of soap was concentrated in a few centers of Province Toulon, Hyres and Marseille which supplied the soap to rest of France. English manufacture tended to concentrate in London. Finer soaps were later produced in Europe from the 16th century, using vegetable oils (such as olive oil) as opposed to animal fats. Many of these soaps are still produced, both industrially and by small scale artisans. Castile soap is a popular example of the vegetable-only soaps derived by the oldest "white soap" of Italy.

In modern times, the use of soap has become universal in industrialized nations due to a better understanding of the role of hygiene in reducing the population size of pathogenic micro organisms. Industrially manufactured bar soaps first became available in the late eighteenth century.

Pears Transparent Soap
Until the Industrial Revolution, soap making was conducted on a small scale and the product was rough. Andrew Pears started making a high-quality, transparent soap in 1789 in London. His son-in-law, Thomas J. Barratt, opened a factory in Isleworth in 1862.

Original Soap Powder
William Gossage produced a low-price good-quality soap from the 1850s. Robert Spear Hudson began manufacturing a soap powder in 1837, initially by grinding the soap with a mortar and pestle. The first trial of Lux soap powder was not like this. They would have produced first white Lux soap; then the ends of the soaps (remnants) were tried like this. Initially bigger soaps were made and cut and not molded as today.

Hindustan Lever
William Hesketh Lever and his brother James, bought a small soap works in Warrington in 1885 and founded what is still one of the largest soap businesses, formerly called Lever Brothers and now called Unilever. These soap businesses were among the first to employ large scale advertising campaigns also.

What is Hand Made Soap? Do Cottage Industries Make Soaps Like This?
Handmade soap has usually, an excess of fat is used to consume the alkali (super fatting), and in that the glycerin is not removed, leaving a naturally moisturizing soap and not pure soap. Additional processing of this glycerin containing soap produces glycerin soap. Super fatted soap, which contains excess fat, is more skin-friendly than industrial soap. This also means when more oil is added the soap becomes slippery.