How World War I Turned Peanut Butter Into a Kitchen Staple

A bloody steak wasn't considered the most patriotic food during World War I. To show support for their nation, many early 20th century Americans served vegetarian peanut loaf for dinner. If that wasn't enough to fill them up, they might have enjoyed a creamy bowl of peanut butter soup on the side.

World War I marked a turning point for the country's relationship with peanut butter. It quickly went from novel processed food to kitchen staple, and Americans used it for more than making snacks and sandwiches. Realizing it was both nutritious and high in calories, the U.S. government promoted the product as a meat alternative at a time when beef was scarce. This might make sense to anyone who's ever eaten a spoonful of peanut butter for breakfast on a lazy morning, but the government's recipes from this era are harder to relate to.

Ahead of National Peanut Butter Day on January 24, the National WWI Museum and Memorial in Kansas City, Missouri, is highlighting the connection between peanut butter and World War I. "At the beginning of the war, transportation and supply-chain issues a real concern," Lora Vogt, curator of education and interpretation at the National WWI Museum and Memorial, tells Mental Floss. "A first priority was providing the amount of nutritious and calorie dense foods needed for American fighting forces."

The American government never implemented rations during the war, but it did call on its people to voluntarily limit their consumption of red meat (as well as wheat and sugar) as a show of support for the troops. As part of this campaign to get people to adapt their eating habits at home, the government published Win the War in the Kitchen, a cookbook featuring substitutions for ingredients that were scarce at the time.

The peanut butter section of the book suggested peanut loaf, which was billed as an alternative to meatloaf. It was made by baking a mixture of peanut butter, bread crumbs, rice, and seasonings in a loaf pan. Like the original dish, it was meant to be served with ketchup. The book's recipe for peanut butter soup calls for peanut butter, milk, water, potato starch, and margarine to be milled and strained to a smooth consistency. Both recipes are available to view through the museum's online exhibit, titled "War Fare: From the Homefront to the Frontlines."

Many of the recipes from Win the War in the Kitchen recommended swapping fresh ingredients with processed foods. "Technological developments for processing and preserving foods advanced significantly in the late 19th and early 20th centuries in the ," Vogt says. "The supply needs of a nation at war certainly impacted marketing messages—not just from the companies but across the country—and influenced the public’s willingness to try or more regularly add manufacturer-provided foods to their table."

Hearty meals built around peanuts predate America's wartime kitchens. West Africans started making savory peanut stews shortly after the legume arrived on the continent via South America—though they didn't use products from jars and cans.

Though peanut loaf didn't become a staple of American cuisine, peanut butter didn't leave pantries in the U.S. following World War I. It's eaten as breakfast, lunch, and snacks today, and if you have the right ingredients at home, there's nothing stopping you from having it for dinner.