Impossible Burger’s 'Blood' Comes From Soybean Roots

The lab-produced soy leghemoglobin is holding up FDA approval for the brand.

Impossible Foods' meatless Impossible Burger is becoming increasingly popular across the United States, with almost 50 different American restaurants now serving it. However, the company is still working with the F.D.A. to answer questions about its secret ingredient, which provides all of the inherent “meatiness” that we crave.

According to the New York Times, the substance, known as heme, comes from soy leghemoglobin and is found naturally in the roots of soybean plants. When soy leghemoglobin breaks down, heme is released, giving the meat substitute a meat-like texture and producing the burger's famous bloodless "bloodiness."

While the F.D.A. remains concerned that, “[heme] has never been consumed by humans and may be an allergen,” Impossible Foods spokesperson Rachel Konrad says that the company has conducted extensive testing of their popular product. "Soy leghemoglobin has been extensively analyzed in rigorous safety tests by the world’s leading experts on food safety and allergenicity and those experts have repeatedly concluded that it’s safe to eat."

Along with working with one of the world's foremost food allergenicity experts (a cofounder and co-director of the University of Nebraska’s Food Allergy Research and Resource Program), Konrad says of Impossible Foods, "We clearly label our product as containing wheat and soy also in compliance with federal regulations." Impossible Foods also states that all restaurants where the Impossible Burger is sold comply with federal regulations about labeling.

Impossible Foods can and will continue to sell their burgers without full F.D.A. approval, even as they resubmit to the agency. “We respect the role the F.D.A. plays in ensuring the safety of our food supply, and we believe the public wants and deserves transparency and access to any information they need to decide for themselves whether any food they might eat is safe and wholesome,” says Konrad.

Founded in 2011 by a Stanford chemist, Impossible Foods has received more than $250 million in private funding and is served at such restaurants as David Chang's Momofuku Nishi, Chris Cosentino's Cockscomb and burger chains Umami Burger and Hopdoddy.

In the meantime, Impossible Foods continues their coast-to-coast expansion, but they've already got some stiff competition as Beyond Burgers hits grocery stores. If the thought of a juicy vegan burger has you salivating, here are some of our favorite recipes for making meat-free (and "blood"-free) burgers at home.

Updated Aug. 9, 2017 to include clarifications from Impossible Foods.