From Luxury to Necessity​—A History of Soap

FEW products are as common or as useful as soap. From babyhood to old age, it is a part of our daily life. Since it was first manufactured in the obscure past, soap has gradually been transformed from a luxury item into a daily necessity.

Indeed, one 19th-century chemist declared that the quantity of soap consumed by a nation was an accurate measure of its wealth and civilization. Today it is regarded as essential to hygiene and good health. How did this important product become a feature of daily life?

Ancient Times

Little evidence exists for the use of soap in personal hygiene before the Common Era. True, the King James version of the Bible states at Jeremiah 2:22: “Thou wash thee with nitre, and take thee much sope [soap].” Yet, there are reasons to doubt that this is a reference to what we know as soap​—whether bars, powder, or otherwise. A modern translation of the prophet’s words reads: “Take to yourself large quantities of lye,” an alkali cleanser that is far different from the soap in use today.

The Greeks and later the Romans typically made use of perfumed oils for cleaning their bodies. They may have learned the art of soapmaking from the Celts. In his work Natural History, first-century Roman writer Pliny the Elder uses the Gallic word saipo, from which, it is said, we derive the word “soap.”

In the centuries that followed, there were few references to the use of soap, although during the Middle Ages, Italy, Spain, and France did establish themselves as centers of soap manufacture. Despite efforts toward mass production, however, it seems that soap was used very little in Europe. In fact, as late as 1672, when a German well-wisher sent an aristocrat a packaged gift of Italian soap, he saw fit to enclose a detailed description of how to use the mysterious product!

Early Soap Production

One of the first detailed recipes for soap appears in a 12th-century compilation of trade secrets for artisans. Over the years the chemical process for its production has remained fundamentally unchanged. Oils and fats from various sources were boiled with a caustic alkaline solution in a process that produces a crude soap. This reaction is called saponification.

Understandably, the quality of the soap produced depended on the materials used. Wood ash and animal fats were used in rudimentary soapmaking, and with these ingredients early homesteaders in the United States produced a brown, jellylike soft soap for their daily  use. Tallow, the rendered fat from cattle and sheep, was the main ingredient for both soap and candles of the time, so tradesmen called chandlers * often made and sold both items. Adding salt at the end of their soap-boiling process allowed them to produce hard, easily transportable bars, which they scented with lavender, wintergreen, or caraway.

Traditionally soaps produced in southern Europe were made from olive oil. Soapmakers in colder climes continued to use tallow. Some even resorted to fish oils. Though adequate for laundry use, these soaps were not particularly desirable for bathing! Fats and oils, though, are only part of the soap story.

From Handicraft to Industry

The alkali required for soapmaking was for many centuries produced from the ashes of select plants, including seaweed. In Spain the saltwort plant was burned, producing an alkaline ash called barilla. Combining it with locally produced olive oil resulted in a high-quality white soap called Castile soap.

The 18th century saw a rising international demand for potash for use in the manufacture of soap, glass, and gunpowder. * About 1790, Nicolas Leblanc, a French surgeon and chemist, developed a process for the production of alkali from common salt. Later, chemists succeeded in producing caustic soda from brine. Such developments paved the way for the industrialization of the manufacture of soap.

Soap Gets a Good Name

The late 19th century was a time of momentous reforms characterized by efforts to educate people in health and hygiene. Yet, the soap of the time remained for the most part a disagreeable brown mass tainted with remnants of raw alkali that irritated the skin. It was still handmade, crudely boiled in cauldrons. It reached the public as anonymous bars that had to be sliced into lengths by the grocer and sold by weight.

Some soap lathered liberally but sweated drops of oil that made fingers greasy and in time went rancid. Producers, increasingly sensitive to the demands of the public, began to include additives such as citronella to mask the nauseating odor with a pleasant perfume reminiscent of lemon.

Further improvements were at hand. Vegetable oil soaps, with their more favorable characteristics, grew popular. Revolutions in transport gave soapmakers easier access to rich sources of luxurious ingredients. West Africa was the home of the oil palm, and a brightly colored buttery substance extracted from its fleshy fruit became a key ingredient  in soaps and cosmetics. From islands of the Pacific came copra, the dried flesh of the coconut, from which coconut oil is extracted. With exotic ingredients drawn from distant places, soap’s image began to change for the better.

Manufacturers understood the natural desire for cleanliness. Consumers had to be convinced that soap was indispensable. Advertisers were soon linking products and their results to such things as honey, sunlight, and snow. Others reworked famous artwork giving their advertisements​—and soap—​an image of refinement and culture. By the turn of the century, soap was a product with a global market. It fueled an advertising industry. In 1894, slogans promoting soap even appeared on the back of postage stamps in New Zealand. Soap now had a good name.

Modern Manufacture

Early industrial manufacture involved boiling ingredients in huge open pans. A skilled operator controlled the process by troweling. From the way soap slid off a heated hand trowel, he could judge whether the ingredients or process needed modifying.

Today soap manufacturing involves three general steps. The first is saponification, which involves reacting various oils or fats with alkali in order to produce neat soap and glycerol in a mix that contains about 30 percent water. At times, this step is still carried out by means of the boiled-kettle process, but most modern soap producers use computerized saponification systems. The second step is drying, which uses heat-, vacuum-, and spray-drying to convert the neat soap into small pellets containing only about 12 percent water. The third and final step is called finishing. The pellets are mixed with perfume, color, and other additives that will make the soap distinctive and fragrant. Bars are extruded and stamped into their characteristic shape in a soap press. Consumer demands now mean that household soaps increasingly feature fruit fragrances and herbal extracts, making soap use a “natural,” more invigorating experience!

Although remarkable advances in understanding the chemistry of detergents have been made and their manufacture revolutionized, traditional soap has retained its popularity. Few would deny that for hygiene and good health, soap is a necessity. Still, it seems odd that in an age so marked with uncleanness on a moral and spiritual level, physical cleanliness is now more attainable than ever. Cleanliness of the surface, though, is most valuable when it reflects purity of the inner person.

[Footnotes]

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Soapmaking in early North America

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“Bubbles,” by Sir John E. Millais, was used as a soap advertisement

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Traditional soap manufacturing using the boiled-kettle process

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Top: Victoria & Albert Museum, London/Art Resource, NY; bottom: © Jeff Greenberg/Index Stock Imagery