Inventing the dishwasher
Deep Dives
Explore related topics with these Wikipedia articles, rewritten for enjoyable reading:
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Josephine Cochrane
11 min read
The central figure in the article who invented the first commercially successful dishwasher. Her full biography would provide context on her motivations, the social position of women inventors in the 19th century, and how she built her company into what became KitchenAid.
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World's Columbian Exposition
15 min read
The 1893 Chicago World's Fair mentioned in the article was a pivotal moment for Cochrane's dishwasher commercialization. This exposition introduced many technologies to mass audiences and shaped American consumer culture in ways readers may not appreciate.
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Rural electrification
13 min read
The article notes that dishwasher adoption was limited by electricity access, growing from under 10% to universal coverage. The rural electrification movement explains how this infrastructure expansion happened and why it took decades, providing crucial context for understanding appliance adoption patterns.
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Soap is an ancient innovation: a Sumerian text from around 2200 BC gives a basic recipe for making soap. But early soap was mostly used to wash clothes, and sometimes for bathing. For kitchen dishes and eating utensils, people made do with cheaper and more readily available materials.
Sand has been used to scour dishes for thousands of years. It’s easy to find and great for physically scrubbing food detritus off of wooden or metal dishes. Many other natural abrasive substances have been used too. In India, traditional dishwashing materials ranged from jute fiber to rice husk to eggshells. In England, the horsetail plant, Equisetum hyemale has been known as ‘scouring rush’ or ‘pewterwort’, and John Gerard’s 1597 botanical reference book explains that the plant’s roughness ‘is not unknowen to women, who scowre their pewter and wooden things of the kitchen therewith’.
When scouring with physical abrasives was not enough to remove grease, the women described by Gerard could turn to the chemical properties of ash. Wood ash contains potassium carbonate. When it’s leached in water, it creates lye, an alkaline solution of potassium hydroxide, which can be combined with an oil or fat to form soap. In essence, washing a greasy dish with ash and water creates soap on a micro scale. The use of wood fires to heat homes and cook food meant that ash was available in abundance.
That would change in the early modern period, when households started switching from wood to coal. In London, the shift began around 1570 and was almost complete by 1600, making wood ash more scarce. Without ash to cut the grease, Londoners began using ready-made soap to wash dishes.
Soap introduced a new requirement: hot water. Hot water is helpful when washing with ash, but not needed when scouring with sand. In fact, Ruth Goodman, in her book The Domestic Revolution, reports that for sand-scouring, cool water actually works better. The soaps available at the time, by contrast, only worked effectively when activated by hot water. So the new soap-and-hot-water dishwashing regime was both prompted by the switch to coal and fueled by it.
In the mid-nineteenth century, inventors made the first steps ...
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