The current Coronavirus pandemic has given us a renewed appreciation for a very old friend. The humble bar of soap has been transformed from a simple household item to our number one weapon in the fight against the spread of this unseen enemy.  

It feels like soap has been with us for centuries but few of us know the history of this unsung hero.

Judith Ridner, Professor of History at Mississippi State University explores some of soap’s “dirty” secrets.

Ancient Origins

Ancient Mesopotamians were first to produce a kind of soap by cooking fatty acids – like the fat rendered from a slaughtered cow, sheep or goat – together with water and an alkaline like lye – a caustic substance derived from wood ashes. The result was a greasy and smelly goop that lifted away dirt.

An early mention of soap comes in Roman scholar Pliny the Elder’s book “Naturalis Historia” from A.D. 77. He described soap as a pomade made of tallow – typically derived from beef fat – and ashes that the Gauls, particularly the men, applied to their hair to give it “a reddish tint.”

Ancient people used these early soaps to clean wool or cotton fibres before weaving them into cloth, rather than for human hygiene. Not even the Greeks and Romans, who pioneered running water and public baths, used soap to clean their bodies. Instead, men and women immersed themselves in water baths and then smeared their bodies with scented olive oils. They used a metal or reed scraper called a strigil to remove any remaining oil or grime.

By the Middle Ages, new vegetable-oil-based soaps, which were hailed for their mildness and purity and smelled good, had come into use as luxury items among Europe’s most privileged classes. The first of these, Aleppo soap, a green, olive-oil-based bar soap infused with aromatic laurel oil, was produced in Syria and brought to Europe by Christian crusaders and traders.

Aleppo Soap is still manufactured today.

French, Italian, Spanish and eventually English versions soon followed. Of these, Jabon de Castilla, or Castile soap, named for the region of central Spain where it was produced, was the best known. The white, olive-oil-based bar soap was a wildly popular toiletry item among European royals. Castile soap became a generic term for any hard soap of this type.

The settlement of the American colonies coincided with an age (1500s-1700s) when most Europeans, whether privileged or poor, had turned away from regular bathing out of fear that water actually spread disease.

In the new nation, the founding of soap manufactories like New York-based Colgate, founded in 1807, or the Cincinnati-based Procter & Gamble, founded in 1837, increased the scale of soap production but did little to alter its ingredients or use. Middle-class Americans had resumed water bathing, but still shunned soap.

Soap-making remained an extension of the tallow trade that was closely allied with candle making. Soap itself was for laundry. At the first P&G factory, laborers used large cauldrons to boil down fat collected from homes, hotels and butchers to make candles and soap.

Workers tended to soap in large tanks in a French factory circa 1870.

From cleaning objects to cleaning bodies

The Crimean War was the watershed. Thanks to reformers like Florence Nightingale who touted regular washing with water and soap as a sanitary measure to prevent the spread of illness and infection, bathing for personal hygiene caught on. Demand for inexpensive toilet soaps increased dramatically among the masses.

Palmolive ads, like this one stressed the exotic ingredients in the green bar.

Companies began to develop and market a variety of new products to consumers. In 1879, P&G introduced Ivory soap, one of the first perfumed toilet soaps in the U.S. B.J. Johnson Soap Company of Milwaukee followed with their own palm-and-olive-oil-based Palmolive soap in 1898. It was the world’s best-selling soap by the early 1900s.

Soap chemistry also began to change, paving the way for the modern era. At P&G, decades of laboratory experiments with imported coconut and palm oil, and then with domestically produced cottonseed oil, led to the discovery of hydrogenated fats in 1909. These solid, vegetable-based fats revolutionized soap by making its manufacture less dependent on animal by-products. Shortages of fats and oils for soap during World Wars I and II also led to the discovery of synthetic detergents as a “superior” substitute for fat-based laundry soaps, household cleaners and shampoos.

From animal fat to coal tar, what goes in tends to be pretty dirty.

Today’s commercially manufactured soaps are highly specialized, lab-engineered products. Synthesized animal fats and plant-based oils and bases are combined with chemical additives, including moisturizers, conditioners, lathering agents, colors and scents, to make soaps more appealing to the senses.

Whether you prefer pump action soap or the traditional bar variety there’s no doubt our foamy friend will be top of our shopping lists for the foreseeable future.

This article is republished from The Conversation.