How Soap was Born: From Mud and Urine to Modern Detergents

Martin Pitt comes clean about the history of soap

CONTRARY to popular belief, the soap industry does not date back to antiquity. The Mesopotamians, Egyptians, Classical Greeks and Romans did not soap themselves, as we understand it. Washing was with water, sometimes with abrasives as exfoliants and followed with skin cream. They did, however, use cleaning mixtures for textiles and floors, which have sometimes been translated as soap.

However, the earliest cleaning agent was actually mud! Woollen fleeces and later cloth were trampled in the river, and it was noted that certain muds made them cleaner by sticking to grease. The process of preparing wool was called fulling and the best clay is called fuller’s earth. A good deposit has been found in Cyprus with houses dating from 5000 BC, containing lumps of clay similar to those used by the Romans, in the only part of the island with sheep bones. Fuller’s earth has been a major part of cleaning right up to the 20th century.

The second was stale urine, which has a limited saponifying and bleaching action. A Roman public urinal has been found with a pipe leading to a small laundry below. The method was still used by one English cloth factory in 1935.

Mesopotamian texts from about 2200 BC give an account of mixing oil and plant ash to clean cloth. An Egyptian text from 210 BC instructs the supply of castor oil and mineral natron for the cleaning of flax in bleaching houses. Unusually, castor oil does not need to be boiled to be saponified by natron, so some soap may have been formed in the process. More complex mixtures which included an alkali and some oil or resin (as well as other things such as herbs and dried snake skins) are listed by Sumerians and Egyptians for medicine, not for regular use. They might have had some soapy character, but there is no manufactured material which could be described as a soap. However, they did have an extensive perfume industry.

A 19th century excavation of Pompeii (covered by volcanic ash in 79 AD) identified one site as a soap factory, but subsequent archaeologists do not agree. The Romans had an extensive bathing culture but without soap. Wealthy people were covered with oil by a slave, who scraped it off. A document supposedly written by the Greek physician Galen (129–216) describing soap to remove filth from the body was actually written in the 16th century.

A similar situation applied in China. Oil and plant ash were mixed to clean cloth in around 1400 BC, and from about 1000 BC mixtures similar to those of the Egyptians were used as medicines.

Some plants produce chemicals called saponins which can give a little foam, and rubbing with the plant or an extract has been used for religious or medical purification. The Sumerian word for fuller comes from the word for the soapwort plant. In ancient India they were formerly collected and processed on a commercial scale but are much less effective and more expensive than actual soap. The Chinese were fortunate in having Gleditsia sinensis, a tree producing pods called “soap beans” which they used as a detergent.

The beginning