Why it matters: The Impossible Whopper has the unfortunate designation of being announced on April Fools' Day but make no mistake, this isn't a gag. The meat-free Whopper is now being market tested in the St. Louis area and could be offered at your neighborhood Burger King in the not-too-distant future.

One of the nation’s largest fast food chains is teaming up with a Silicon Valley start-up to pump out meatless versions of its iconic burger.

Burger King this week is introducing a meat-free version of its iconic Whopper based on a patty from Impossible Foods. The aptly named Impossible Whopper is being market tested at 59 restaurants in and around the St. Louis area. If successful, the vegetarian creation could soon go nationwide.

Burger King’s chief marketing officer, Fernando Machado, said he has high expectations that it’s going to be big business, not just a niche product.

In testing thus far, Machado said customers and employees haven’t been able to tell the difference between the meaty Whopper and the new version. “People on my team who know the Whopper inside and out, they try it and they struggle to differentiate which one is which,” Machado said.

Burger King isn’t the first nationally recognized chain to adopt a meatless burger. White Castle sells a slider from Impossible Foods in its 380 or so locations; Carl’s Jr. introduced the Beyond Famous Star burger earlier this year courtesy of Beyond Burger.

Lead image courtesy AzirSuratmin via Shutterstock