North Americans weren't the first to grind peanuts—the Inca beat us to it by a few hundred years—but peanut butter reappeared in the modern world because of an American, the doctor, nutritionist and cereal pioneer John Harvey Kellogg, who filed a patent for a proto-peanut butter in 1895. Kellogg’s “food compound” involved boiling nuts and grinding them into an easily digestible paste for patients at the Battle Creek Sanitarium, a spa for all kinds of ailments. The original patent didn’t specify what type of nut to use, and Kellogg experimented with almonds as well as peanuts, which had the virtue of being cheaper. While modern peanut butter enthusiasts would likely find Kellogg’s compound bland, Kellogg called it “the most delicious nut butter you ever tasted in your life.”

A Seventh-Day Adventist, Kellogg endorsed a plant-based diet and promoted peanut butter as a healthy alternative to meat, which he saw as a digestive irritant and, worse, a sinful sexual stimulant. His efforts and his elite clientele, which included Amelia Earhart, Sojourner Truth and Henry Ford, helped establish peanut butter as a delicacy. As early as 1896, Good Housekeeping encouraged women to make their own with a meat grinder, and suggested pairing the spread with bread. “The active brains of American inventors have found new economic uses for the peanut,” the Chicago Tribune rhapsodized in July 1897.

Before the end of the century, Joseph Lambert, an employee at Kellogg’s sanitarium who may have been the first person to make the doctor’s peanut butter, had invented machinery to roast and grind peanuts on a larger scale. He launched the Lambert Food Company, selling nut butter and the mills to make it, seeding countless other peanut butter businesses. As manufacturing scaled up, prices came down. A 1908 ad for the Delaware-based Loeber’s peanut butter—since discontinued—claimed that just 10 cents’ worth of peanuts contained six times the energy of a porterhouse steak. Technological innovations would continue to transform the product into a staple, something Yanks couldn’t do without and many a foreigner considered appalling.

By World War I, U.S. consumers—whether convinced by Kellogg’s nutty nutrition advice or not—turned to peanuts as a result of meat rationing. Government pamphlets promoted “meatless Mondays,” with peanuts high on the menu. Americans “soon may be eating peanut bread, spread with peanut butter, and using peanut oil for our salad,” the Daily Missourian reported in 1917, citing “the exigencies of war.”

The nation’s food scientists are nothing if not ingenious, and peanut butter posed a slippery problem that cried out for a solution. Manufacturers sold tubs of peanut butter to local grocers, and advised them to stir frequently with a wooden paddle, according to Andrew Smith, a food historian. Without regular effort, the oil would separate out and spoil. Then, in 1921, a Californian named Joseph Rosefield filed a patent for applying a chemical process called partial hydrogenation to peanut butter, a method by which the main naturally occurring oil in peanut butter, which is liquid at room temperature, is converted into an oil that’s solid or semisolid at room temperature and thus remains blended; the practice had been used to make substitutes for butter and lard, like Crisco, but Rosefield was the first to apply it to peanut butter. This more stable spread could be shipped across the country, stocked in warehouses and left on shelves, clearing the way for the national brands we all know today. The only invention that did more than hydrogenation to cement peanut butter in the hearts (and mouths) of America’s youth was sliced bread—introduced by a St. Louis baker in the late 1920s—which made it easy for kids to construct their own PB&Js. (In this century, the average American kid eats some 1,500 peanut butter and jelly sandwiches before graduating from high school.)

Rosefield went on to found Skippy, which debuted crunchy peanut butter and wide-mouth jars in the 1930s. In World War II, tins of (hydrogenated) Skippy were shipped with service members overseas, while the return of meat rationing at home again led civilians to peanut butter. Even today, when American expats are looking for a peanut butter fix, they often seek out military bases: They’re guaranteed to stock it.

But while peanut butter’s popularity abroad is growing—in 2020, peanut butter sales in the United Kingdom overtook sales of the Brits’ beloved jam—enjoying the spread is still largely an American quirk. “People say to me all the time, ‘When did you know that you had fully become an American?’” Ana Navarro, a Nicaraguan-born political commentator, told NPR in 2017. “And I say, ‘The day I realized I loved peanut butter.’”

Though the United States lags behind China and India in peanut harvest, Americans still eat far more of the spread than the people in any other country: It’s a gooey taste of nostalgia, for childhood and for American history. “What’s more sacred than peanut butter?” Iowa Senator Tom Harkin asked in 2009, after a salmonella outbreak was traced back to tainted jars. By 2020, when Skippy and Jif released their latest peanut butter innovation—squeezable tubes—nearly 90 percent of American households reported consuming peanut butter.

The ubiquity of this aromatic spread has even figured in the nation’s response to Covid-19. As evidence emerged last spring that many Covid patients were losing their sense of smell and taste, Yale University’s Dana Small, a psychologist and neuroscientist, devised a smell test to identify asymptomatic carriers. In a small, three-month study of health care workers in New Haven, everyone who reported a severe loss of smell using the peanut butter test later tested positive. “What food do most people in the U.S. have in their cupboards that provides a strong, familiar odor?” Small asks. “That’s what led us to peanut butter.”

Sustainable

No American is more closely associated with peanuts than George Washington Carver, who developed hundreds of uses for them, from Worcestershire sauce to shaving cream to paper. But our insatiable curiosity for peanuts, scholars say, has obscured Carver’s greatest agricultural achievement: helping black farmers prosper, free of the tyranny of cotton.

Born enslaved in Missouri around 1864 and trained in Iowa as a botanist, Carver took over the agriculture department at the Tuskegee Institute, in Alabama, in 1896. His hope was to aid black farmers, most of whom were cotton sharecroppers trapped in perpetual debt to white plantation owners. “I came here solely for the benefit of my people,” he wrote to colleagues on his arrival.

He found that cotton had stripped the region’s soil of its nutrients, and yet landowners were prohibiting black farmers from planting food crops. So Carver began experimenting with plants like peanuts and sweet potatoes, which could replenish the nitrogen that cotton leached and, grown discreetly, could also help farmers feed their families. In classes and at conferences and county fairs, Carver showed often packed crowds how to raise these crops.

Since his death in 1943, many of the practices Carver advocated—organic fertilizer, reusing food waste, crop rotation—have become crucial to the sustainable agriculture movement. Mark Hersey, a historian at Mississippi State University, says Carver’s most prescient innovation was a truly holistic approach to farming.

“Well before there was an environmental justice movement, black environmental thinkers connected land exploitation and racial exploitation,” says Hersey. A true accounting of American conservation, he says, would put Carver at the forefront.

Editor's note, January 6, 2021: This story has been updated to clarify that the Inca developed peanut butter hundreds of years before North Americans, and not thousands as originally stated.

Kate Wheeling | READ MORE

Kate Wheeling is a former staff writer at Pacific Standard.

Emily Moon | READ MORE

Emily Moon is a journalist whose work has appeared in Pacific Standard, Chicago Sun-Times and The Herald-Times.