The True Story Behind Netflix’s Unfrosted, Jerry Seinfeld’s Pop-Tarts Movie

Jerry Seinfeld’s Unfrosted, a feature film about the heated race to create the toaster pastry Pop-Tarts, starts streaming today (May 3) on Netflix. In his directorial debut, Seinfeld also stars as Kellogg’s head of development, facing cereal mascots and milkmen up in arms because they’re afraid that a breakfast food that doesn’t require milk is going to run them out of business.

The movie, which also stars Hugh Grant and Amy Schumer, was more than a decade in the making. Seinfeld and Unfrosted screenwriter Spike Feresten, a Seinfeld writer, joked about making a movie based on the comedian’s favorite breakfast as far back as 2013. But then came the COVID-19 pandemic, when Seinfeld had to stop doing standup, and he and Feresten took a stab at turning the inside joke into a movie for the outside world. Both writers found the kids cereal business inherently hilarious, Feresten tells TIME, imagining “serious men in suits inventing silly things for kids.”

While the movie is a total farce, it’s grounded in the historic rivalry between America’s biggest makers of breakfast cereal. Kellogg and Post were both founded in Battle Creek, Michigan, and had a long history of competing against each other. In the early 1900s, C.W. Post stole a Kellogg recipe for corn flakes, which he dubbed ‘post-toasties.’ Howard Markel, a historian who wrote a book about Kellogg, describes the companies to TIME as always “fighting like cats and dogs, like Ford and General Motors.”

A space race for breakfast foods

Fast-forward to the 1960s, when Post and Kellogg were competing to develop a breakfast food for toasters at the same time. The movie likens the race to the space race, with Kellogg introducing its “taste pilots” as if they were NASA astronauts. In reality, Post had announced that its “Country Squares” were in the works, wrapped in foil, but Kellogg beat them to the market in 1964. 

The key ingredient to Kellogg’s Pop-Tart success was recruiting Bill Post in 1963, who was managing a Hekman (later Keebler Food Co.) plant in Grand Rapids, Michigan. Post took home some Pop-Tart prototypes to his children, and they were a hit. His children “used to ask me, ‘Bring those fruit scones home,’" he told the Associated Press in 2003. "That’s what we called them at first, internally. Fruit scones. ‘Bring some of those home, will you Dad?’” In the movie, children do play a key role as taste-testers: Seinfeld discovers kids snacking on leftovers in Post’s dumpster.

Kellogg’s Pop-Tarts were a hit with a test market in Cleveland in late 1963. The following year, Kellogg immediately sold out of the four original flavors—strawberry, blueberry, apple currant, and brown sugar cinnamon. Kellogg’s added frosting in 1967 and then sprinkles in 1968, per Post’s suggestion. Now Pop-Tarts come in more than two dozen flavors, and factories churn out about 7 million Pop-Tarts a day. At one point, Bill Post drove a car with a vanity plate that read “Pop Tart.”

Pop-Tarts were a product of its moment. The Pop-Tarts’ website says the name—coined by Kellogg executive William LaMothe—is a play on the popular Pop-Art movement of the 1960s. And as women climbed the ranks at their jobs, empowered by the women’s movement of the 1960s and 1970s, they needed a breakfast their kids could eat quickly, according to Heather Arndt Anderson’s Breakfast: A History.

Tony the Tiger

Several characters in the movie are fictionalized versions of real people. Jack LaLanne, a Kellogg taste pilot played by James Marsden, went on to pioneer home exercise, and in the movie, he inspires Pop-Tarts’ foil packets by parading around in a puffy foil bodysuit. Thurl Ravenscroft (Grant) really did come up with the “Grrrrreeeat!” slogan for Frosted Flakes mascot Tony the Tiger. As he joked to the Orange County Register in 1996, "I'm the only man in the world that has made a career with one word: Grrrrreeeat!" Schumer plays philanthropist and Post executive Marjorie Post, depicted as so hungry for business that she flies to Moscow to pitch cereal ideas to the Soviets. In reality, she stepped down as Post’s corporation director in 1958, six years before the Pop-Tart came out.

The Bill Post who helped create Pop-Tarts won’t be able to see the Netflix film, as he passed away on Feb. 10, at the age of 96. The filmmakers did not work with him on the film, but Seinfeld’s Kellogg executive character Bob Cabana is loosely based on him. His name was changed because screenwriter Feresten thought having a character named Post working for Kellogg in a movie about Kellogg and Post feuding would be confusing for viewers.

Seinfeld and Feresten started writing what would become Unfrosted over Zoom after Hollywood productions stalled during the COVID-19 pandemic. Feresten, whose favorite Pop-Tart is frosted blueberry, describes the film to TIME as “a Seinfeld episode with a very big budget.”

Pop-Tarts may not be the most wholesome breakfast—they’re full of highly processed ingredients—but the movie is pure, wholesome fun.