How Burger King's "Impossible Whopper" Tastes Like Flame-Broiled Beef

The jewel in the Burger King crown has long been the Whopper, a flame-grilled, quarter-pound of muscle squished between lettuce, tomatoes, and two soft buns wrapped in paper, boasting: “100% Beef With No Fillers.” But on Monday, the burger giant unveiled the “Impossible Whopper,” a plant-based doppelgänger of the classic sandwich that seems likely to be a lasting plant-based replacement because of its well-crafted good looks and uncanny meaty chemistry.

"The Impossible Whoppers are shipped ready to be flame-broiled on Burger King’s equipment in the exact way the burgers from cows are.

The Impossible Whopper is created by Impossible Foods, the biotech startup known for its all-vegetarian burger that has the texture, smell, and “bloodiness” of beef. Its products have already been adopted by well-known chains like Momofuku, Bareburger, and White Castle, but Burger King is by far the most popular chain to do so. According to Jessica Appelgren, a press representative for Impossible Foods, Burger King pulled out all the stops to keep the customer experience as faithful to its original meat-based product as possible.

“The Whopper version of the Impossible Burger was created to match the form factor of the original Whopper, requiring Impossible Foods to add a new manufacturing line in our Oakland factory to produce the Impossible Whoppers,” Appelgren tells Inverse. “The Impossible Whoppers are shipped ready to be flame-broiled on Burger King’s equipment in the exact way the burgers from cows are.”

The Impossible Whoppers are being rolled out in 59 restaurants in the St. Louis area, but given that the company has overhauled part of a factory to accommodate the demand from Burger King, it seems clear that it’s expecting to have a much wider audience.

The Heme Dream

One reason Burger King can afford to take such a gamble on a beefless patty is because the Impossible Foods product is uncannily beef-like. Though other high-profile, plant-based meat companies exist — the pea-and-beet-based Beyond Meat is its most direct competitor — Impossible Foods has dominated the field with its use of the protein heme, which helps to give meat its unmistakably meaty flavor.

In animal and human blood, heme is a key part of the molecule hemoglobin, which carries oxygen around the body with the crucial help of iron atoms. That’s why blood, when sucked from a paper cut, can have a metallic flavor.

That flavor is hardly appetizing on its own, but Impossible Foods has bet on the idea that it’s a crucial part of making plants taste like meat. Heme, crucially, doesn’t need to be sourced from animals. In a previous interview, company representative Lance Ignon told Inverse that the heme Impossible Foods uses is sourced from the root nodules of soybeans, where it’s part of a protein called “leghemoglobin.” This hemoglobin-like molecule also contains iron atoms, lending a familiarly bloody taste.

Importantly, the company has also figured out how to source leghemoglobin efficiently. Harvesting it from individual plants is impractical, so researchers instead took the gene that encodes leghemoglobin from soybeans and inserted it into yeast, which can pump it out much faster, and is less energy-intensive, than a soybean farm.

First Impressions

Some citizens of St. Louis, perhaps still reeling from a spate of recent Twitter jokes about the city’s unconventional food traditions, were confused about whether the introduction of the Impossible Whopper in their city was an April Fools’ joke. But early Twitter reviews are in, and it’s got vegetarians and omnivores alike convinced.

“I had to double check after my first bite to make sure they didn’t give me meat it was that good!” tweeted Aprylete Russell, using the hashtag #vegetarian. Writing for the local Riverfront Times, Danny Wicentowski commented that the Impossible Whopper costs a dollar more than usual but that the “essential ‘Whopperness’ is there, and it hits the spot.”

The all-veggie patty’s adoption by fans of a huge chain such as Burger King could be a turning point for this relatively new innovation — and it could have especially great effects if it’s adopted beyond the US. As the climate continues to warm, it will become even more taxing on the environment to farm animals; developing nations, meanwhile, are expected to increase their demand for meat as their populations grow and become more affluent.

Lab-grown meat is emerging as a promising technology, but critics have pointed out that it’s only as green as the energy that powers it. For consumers who have the option to choose, a plant-based burger will always be a greener one — but fortunately, it no longer has to taste that way.