Vegetable oil

• 1. Introduction

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  Vegetable oil is older than written history. Archaeological evidence shows olives were being turned into olive oil by 6000 BC, in what is now Israel. That single golden liquid, pressed from a fruit, has lit lamps, preserved the dead, greased the machines of an empire, and ended up in nearly everything on a modern supermarket shelf. Vegetable oils are oils extracted from seeds or from other edible parts of plants. Like animal fats, they are mixtures of triglycerides. Some come from seeds, such as soybean, canola, grapeseed, and cocoa butter. Others come from elsewhere in the plant, such as olive, palm, and rice bran oil. How did a substance pressed for cooking and lamplight become a global commodity, an engine fuel, and a boat varnish all at once? Why did one oil pressed from a tropical fruit overtake all the rest? And how does a thin, flavorless oil quietly win a market by displacing the oil that came before it? The answers run through chemists, carmakers, and a clever bit of marketing built around a single invented word.

• 2. Lamps And Mummies

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  In ancient Egypt, plant oils were part of how the dead were prepared for eternity. Cedar oil, cypress oil, and olive oil were all used during the mummification process. The same oils that anointed corpses also fed the living, lit their homes, and treated their ailments. Vegetable oils served as lighting fuel for lamps, as cooking fat, as medicine, and as lubrication, a spread of uses that long predates any factory. Palm oil carried its own deep history in West and Central African countries, where it had long been recognized as a staple. European merchants trading with West Africa occasionally bought palm oil to bring home as a cooking oil for European kitchens. That modest trade hints at the larger role palm oil was about to claim once Britain's machines needed something to keep them turning.

• 3. Grease For An Empire

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  British traders came to prize palm oil for a use that had nothing to do with food. They wanted it as an industrial lubricant for the machinery of Britain's Industrial Revolution. The oil that had cooked West African meals now kept English factory engines from seizing. It also lathered up across the empire as soap. Palm oil formed the basis of soap products such as Lever Brothers' Sunlight, from the company now known as Unilever, and the B. J. Johnson Company's Palmolive, now part of Colgate-Palmolive. By around 1870, palm oil had become the primary export of some West African countries. The same oil would later outgrow every rival, but first chemists had to figure out what fat actually was.

• 4. Cracking The Chemistry

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  In 1780, Carl Wilhelm Scheele showed that fats were derived from glycerol. Thirty years later, Michel Eugene Chevreul worked out that these fats were esters of fatty acids and glycerol. That understanding set the stage for reshaping oils on purpose. Wilhelm Normann, a German chemist, introduced the hydrogenation of liquid fats in 1901. His process created what later became known as trans fats, and it opened the door to mass production of margarine and vegetable shortening. Hydrogenation works by raising a blend of vegetable oil and a metal catalyst, typically nickel, to very high temperatures in a near-vacuum, then introducing hydrogen. The carbon atoms break their double bonds, each binding instead to a hydrogen atom. A fully hydrogenated oil, a saturated fat, has had all its double bonds turned into single bonds. The danger lived in the half-finished version. Partial hydrogenation turns unsaturated cis fatty acids into trans fatty acids, and partially hydrogenated oils have been linked to a higher risk of death from coronary heart disease. Those concerns eventually drove regulations mandating their removal from food.

• 5. The American Kitchen Reinvented

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  As early as 1911, Procter & Gamble marketed cottonseed oil as a creamed shortening called Crisco. Ginning mills had been glad for anyone to haul away their cotton seeds. The extracted oil was refined, partially hydrogenated into a room-temperature solid that mimicked lard, and canned under nitrogen gas. Against the rendered lard the company already sold, Crisco was cheaper, easier to stir into a recipe, and able to sit on a shelf for two years without turning rancid. Soybeans drew an even stranger cast of champions. Henry Ford set up a soybean research laboratory, developed soybean plastics and a soy-based synthetic wool, and built a car almost entirely out of soybeans. Roger Drackett, flush from the success of Windex, poured money into soybean research as a smart investment. By the 1950s and 1960s, soybean oil was the most popular vegetable oil in the United States. It now sits second only to palm oil. In 2018-2019, world soybean oil production reached 57.4 million tonnes, led by China at 16.6 million tonnes, the US at 10.9 million tonnes, Argentina at 8.4 million tonnes, Brazil at 8.2 million tonnes, and the EU at 3.2 million tonnes.

• 6. Fuel In The Tank

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  On the 10th of August 1893, in Augsburg, Germany, an engine ran on its own power for the first time, burning nothing but peanut oil. Rudolf Diesel had designed his engine to run on vegetable oil, hoping the choice would appeal to farmers who already had fuel growing in their fields. In remembrance of that run, the 10th of August is now declared International Biodiesel Day. The first patent on biodiesel was granted in 1937. Petroleum shortages kept reviving the idea, spurring research into vegetable oil as a diesel substitute in the 1930s and 1940s, and again in the 1970s and early 1980s, when straight vegetable oil drew its highest level of scientific interest. The 1970s also saw the first commercial enterprise that let consumers run straight vegetable oil in their vehicles. Biodiesel, made from oils or fats through transesterification, proved more practical. Led by Brazil, many countries built biodiesel plants during the 1990s, and it is now the most common biofuel in Europe. In France, biodiesel is blended at a rate of 8 percent into the fuel used by all French diesel vehicles.

• 7. Inventing Canola

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  In the mid-1970s, Canadian researchers developed a low-erucic-acid rapeseed cultivar, and then faced a marketing problem. The word rape was not considered ideal for selling a kitchen oil, so they coined a new name, canola, from Canada Oil low acid. The U.S. Food and Drug Administration approved the canola name in January 1985, and American farmers planted large areas that spring. Canola oil is lower in saturated fats and higher in monounsaturates. It is very thin, unlike corn oil, and flavorless, unlike olive oil. That blankness became its strategy. Canola largely succeeds by displacing soy oil, just as soy oil largely succeeded by displacing cottonseed oil. The pattern is a relay of one neutral oil quietly replacing the last.

• 8. Pressed, Dissolved, Counted

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  Oil leaves a plant by one of two routes. Mechanical extraction, called crushing or pressing, uses devices like the expeller press, the screw press, the ram press, and the ghani, a powered mortar and pestle used mainly in India. Solvent extraction instead dissolves the oil out, most often with petroleum-derived hexane, which gives higher yields faster and cheaper. The gap is plain in the numbers for extracting mowrah butter in India: the ghani pulls out 20 to 30 percent, expellers 34 to 37 percent, and solvent 40 to 43 percent. Yield per acre tells its own story. Oil palm is by far the highest-yielding crop, producing about 4 tons of palm oil per hectare per year, against 1.4 for coconut, 0.75 for canola, 0.6 for sunflower, and 0.45 for soybean. That advantage helps explain the global surge. Between 2000 and 2022, world production of vegetable oils rose 130 percent to 212 million tonnes, with palm oil accounting for the largest jump and overtaking soybean oil as the main vegetable oil produced in 2006.