The science behind the most explosive breakfast pastry
Ask any kid: Pop-Tarts are the ideal breakfast. They’re delicious. They’re unhealthy. They’re available in wacky flavors like s'mores and root beer. But what most Pop-Tart fans, young and old, don’t know is that their breakfast pastry is also extremely flammable. Thomas Nangle discovered this in 1992, when his Pop-Tarts got stuck in a friend’s toaster. The pastry quickly caught fire, scorching the kitchen. Nangle sued Kellogg for damages, and the breakfast behemoth eventually paid him $2,400.
Miami Herald columnist Dave Barry discovered the story a year later. Delighted, he recreated the scenario. He documented his findings (“scary flames...shooting up 20 to 30 inches out of both toaster slots”) in a column, concluding that President Clinton could use the knowledge for missile defense. The national syndicated column created a flurry of interest in the subject. “I recall people being pretty excited. This was before the Internet was big, so it was easier to get people excited,” Barry said in an email. “Also people sent me Pop-Tarts. I don’t know why. Maybe they were trying to kill me.”
A Texas A&M professor ran his own experiment (“Abstract: Strawberry Pop Tarts may be a cheap and inexpensive source of incendiary devices”), as did someone calling themselves the director of the “American Institute of Pyrotartology” (“Fragrant Pop-Tart odor has now changed in character to rancid pseudo-strawberry stench.”) Barry and David Letterman even tried it on Letterman’s show. But it didn’t keep people from accidentally overheating their Pop-Tarts. In 2000, a woman left cherry Pop-Tarts in the toaster while walking her kids to preschool. She came back to her house in flames and sued Kellogg for $100,000.
When I read the Barry column recently, I wasn’t sure his experiment would still work. Surely, after the lawsuits, Kellogg’s had changed the recipe to make Pop-Tarts less flammable? I first attempted it with a toaster from Goodwill. It didn’t get hot enough, even though I weighed down the lever with a piece of heavy pottery. My frosted strawberry Pop-Tarts smoked but didn’t ignite. I tried again with my parents’ newer toaster. It started smoking after a few minutes, producing angry clicks and twangs, but an auto-override function kicked in and it stopped heating.
Annoyed, I bought a new toaster, the cheapest one at Target. I put it in my fireplace, plugged it in, and set it to the highest setting. Instead of trying to override the lever, my boyfriend and I immediately pressed it down every time it popped. After 12 minutes, a fire started. The flames climbed to the top of our fireplace (a little more than two feet), dying down within ten minutes. Later, I tried to clean the toaster. The pastry had dissolved into miniscule crumbs, the melted frosting covering the heating elements with a shiny black lacquer.
So, yes: Pop-Tarts are still flammable. But why? “Pop-Tarts are a pretty remarkable bit of food engineering because they’re designed to stay somewhat moist over time and not get completely dried and desiccated,” said Gavin Sacks, associate professor of food science at Cornell. To achieve Pop-Tart’s stability, Kellogg food scientists have to worry about something called water activity, or how much the water in a food product moves around. When there’s low water activity, water is less likely to interact with other materials (like yeast and bacteria) and cause mold. But that low water activity keeping them shelf stable also makes them flammable.
When a fire breaks out, people throw water on it. Pop-Tart ingredients like xanthan gum reduce water activity and humidity, so there’s less water evaporating off to combat a fire, Sacks said. Plus, “this product is ten percent fat by weight, with most of that coming from oils,” he added. “It’s going to ignite like an old-fashioned oil lantern.”
When those oils heat, the risk of fire increases. “Gaseous fuel (vapors from the heated oils in the tart) need to mix with oxygen in the air before they can burn,” Joe Sesniak, a public information officer for the International Association of Arson Investigators, said in an email. “There isn't much air flow into the toaster itself during a fire so the preheated vapors naturally rise out of the toaster and mix with air where they burn above the toaster.”
After the lawsuits, Kellogg added a stern warning to Pop-Tart boxes: “Caution: if pastry is overheated, frosting/filling can become extremely hot and could cause burns. Due to possible risk of fire, never leave appliance unattended.” Yet people continue to incinerate their Pop-Tarts, for investigative purposes, or simply because they can. And they’re likely to continue doing so, as long as Pop-Tarts maintain their popularity—in 2014, the Wall Street Journal reported that Pop-Tart sales have increased every year for the past 32 years. So how does Dave Barry feel, 24 years later, about introducing Americans to the irresistible, unwise hobby of setting their Pop Tarts aflame?
“I’m very proud to have been a pioneer in this field of research,” he wrote. “I’m not saying I should get a Nobel Prize. But I’m not saying I shouldn’t, either.”