How soybeans took over the American diet – without anyone noticing

U.S. farmers will produce a record-breaking harvest of 4.52 billion bushels of soybeans in 2026, according to projections from the U.S. Department of Agriculture. At 60 pounds to the bushel, that is roughly 800 pounds of soybeans for every American.

Most people don't think of themselves as soybean consumers. Few sit down to a plate of soybeans, but soy is hiding in plain sight throughout the American diet. Soybean oil appears in salad dressings, mayonnaise, baked goods, infant formula, snacks and fried foods; soy lecithin emulsifies chocolate and bread; and soy protein fortifies energy bars, breakfast cereals and canned soup.

As an environmental historian who studies agriculture and food, I seek to understand a peculiar transformation: How did a plant that most Americans barely ate a century ago become a ubiquitous food ingredient without people noticing?

A Chinese crop becomes a North American commodity

Chinese farmers domesticated the soybean (Glycine max) from its wild ancestor, Glycine soja, between 6,000 and 9,000 years ago. By the first millennium B.C.E., it ranked among the "five grains," the staple crops recognized in early Chinese texts.

Soybeans came to North America much later. In 1764, an English sailor named Samuel Bowen arrived in Savannah, Georgia, with a handful of soybeans, a souvenir from several years spent in China. The following spring, Georgia's surveyor-general Henry Yonge planted Bowen's unfamiliar "Chinese vetches" and harvested three crops in a single season. In 1767, Bowen received a British patent for his method of producing soy sauce, a fermented condiment resembling the soy sauce already imported from Asia. The enterprise faded into obscurity after Bowen's death, and soybeans remained little more than a curiosity in North America.

That changed around 1900. U.S. Department of Agriculture plant explorer Frank Meyer collected dozens of soybean varieties in China, many of which government researchers Charles Piper and William Morse planted at the department's Arlington Experimental Farm in Virginia. They compared imported varieties for such traits as maturity, yield, plant form and suitability for seed or hay, selecting strains that showed promise for cultivation in the United States. Piper and Morse then distributed promising varieties to agricultural experiment stations around the country, where researchers determined which ones performed best under local conditions.

At first, Americans mostly grew soybeans as forage and livestock feed. The emergence of industrial crushing in the 1910s transformed the crop. Initially, processors squeezed oil from the beans mechanically. Over the next few decades, they increasingly used chemicals to extract the oil, which efficiently separated the bean into two valuable commodities: protein-rich meal for livestock, and oil for a wide range of uses, including margarine, paint and soap.

Henry Ford's vegetable interest

No industrialist embraced the soybean more enthusiastically than Henry Ford. In 1933, Fortune magazine marveled that Ford was "as much interested in the soya bean as he is in the V-8" engine.

Ford believed that industry and agriculture were "natural partners." Farmers sought new markets for their crops, and auto factories needed raw materials. On 8,000 acres in Michigan, Ford's researchers planted 300 soybean varieties and searched for ways to incorporate the harvest into automobiles.

They succeeded. Soybean oil went into Ford paints, and soybean meal into molded plastic parts. By 1935, Ford was using roughly a bushel of soybeans in the manufacture of every automobile. Six years later, he unveiled a lightweight "Soybean Car," built from 14 soy-derived plastic panels attached to a tubular steel frame.

Ford, whose enthusiasm for agricultural experimentation coexisted with a virulent antisemitism that earned him honors from Germany's Nazi government, also wanted Americans to eat his wonder crop.

His scientists investigated soy milk, soybean "cheese" and soy breads, with mixed results. One employee remembered the experimental soy biscuits as "the most vile-tasting things you ever put in your mouth."

Undeterred, Ford served 30 reporters a soybean luncheon at Chicago's 1934 Century of Progress Exposition. The menu featured soybean purée, soybean cheese, soybean bread, soybean coffee and even apple pie baked in a soybean crust. The journalists were skeptical. One later recalled, "Nothing we newsmen ate that day led us to foresee that soybeans were destined a few years later to become an ingredient in many popular food products, some of them delicious."

They could more readily imagine the bean becoming cattle feed or an industrial raw material – which is exactly how its use evolved, at first.

Soy disappears into the American diet

Ford's soybean cuisine never conquered America's kitchens. Something much more consequential happened. Soy became ubiquitous precisely by becoming invisible.

World War II accelerated the transformation. Cut off from imported fats and oils, U.S. processors turned to domestic vegetable oils, especially soybean oil. After the war, booming livestock production drove demand for protein-rich soybean meal. But crushing all those beans also produced a river of cheap oil. Processors needed markets for what was, in effect, the crop's increasingly abundant second product.

Food manufacturers found them. Adding hydrogen turned soybean oil into solids such as shortening and margarine. The low cost, neutral flavor and abundance of soybean oil made it ideal for processed foods. Between 1942 and 1972, federal figures show the amount of American butter in the market fell from 16.4 to 5 pounds per person, while margarine rose from 2.9 to 11.1 pounds. Cheap soybean oil helped make this transition possible.

By 2008, soybean oil accounted for approximately 80% of the 18 billion pounds of edible oils Americans used annually. It appeared as cooking oil, frying fat, shortening, salad dressing, mayonnaise and an inconspicuous ingredient in packaged foods.

Americans never needed to fall in love with tofu to become ravenous consumers of soy.

From food to fuel

The latest soybean headlines bring the story full circle. Henry Ford dreamed of erasing the boundary between farm and factory. Ninety years later, something remarkably close to that vision has emerged.

Soybeans feed livestock and humans, but their oil also flows into an energy economy shaped by several decades of federal renewable-fuel mandates. A new federal rule finalized in March 2026 increased the amount of renewable fuel that refiners and importers must incorporate into the nation's transportation-fuel supply. These mandates have helped draw growing quantities of domestic soybean oil toward biomass-based diesel production.

Soybean oil becomes biodiesel and aviation fuel, powering school buses and commercial airplanes.

Federal scientists helped transform soy into a viable American crop. Agricultural policies made it cheap and plentiful. Livestock producers created enormous demand for soybean meal. Wartime shortages favored domestic oils. Processors found new uses for the oil. Food manufacturers slipped it into an expanding range of products. Americans still made choices in supermarkets and restaurants, but the menu of cheap possibilities had been shaped long before they arrived.

Soy conquered America not because Americans craved the bean, but because it was remarkably versatile. Its protein could feed a chicken or a pig, its oil could fry French fries or propel a truck, and its lecithin could emulsify chocolate or mayonnaise. It could ship easily, too, with Chinese purchases of American soy becoming an element of the trade war between the Trump administration and China.

That flexibility put the soybean at the intersection of food, agriculture, industry, energy and geopolitics. Ninety years after Ford tried to persuade skeptical reporters to eat soybean pie, his obsession with the crop looks less eccentric than prophetic.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Edward D. Melillo, Amherst College

Read more:

Edward D. Melillo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.