Burger King is trialling a meat-free version of its famous Whopper, rolling out the new “Impossible Whopper” at 59 restaurants in St Louis.

The meatless burger, developed with Impossible Foods, a California-based company that makes plant-based substitutes, is designed to “bleed” like a conventional burger, and uses genetically modified yeast to produce heme, a protein that mimics the flavor of meat.

Burger King insists the new plant-based alternative tastes as good as the real thing. Christopher Finazzo, the chain’s North America president, said: “We’ve done sort of a blind taste test with our franchisees, with people in the office, with my partners on the executive team, and virtually nobody can tell the difference.”

Burger King has offered a veggie burger for years. But the difference between the veggie option and the new no-meat Whopper may be that meat-eaters are more willing to try it. The chain says it will still put mayonnaise on the Whopper’s twin and claims the meat-free patty is not only for those following a plant-based diet.

White Castle, the US burger chain known for tiny, square sliders, currently sells the Impossible Burger product in more than 370 restaurants, and the chain has reported better-than-expected sales.

Impossible Foods has at least one major competitor, Beyond Meat, which sells its Beyond Burger at Carl’s Jr and A&W restaurants in Canada. Beyond Meat will be the first of Silicon Valley’s new generation of food companies to go public. Its initial public offering this spring is expected to raise roughly $150m, analysts told the Guardian, even as the company loses $29.9m per year in its efforts to expand.

Burger King’s new burger may not please budget-conscious customers, though. It will sell the Impossible Burger for about a dollar more than the beef version – in part because of the difficulty plant-based companies have had matching cheap meat prices. Beyond Meat’s burger is also more expensive than most beef alternatives.

Impossible Foods’ main pitch is for environmental sustainability. Intensive animal agriculture is a major source of greenhouse gas, water use and pollution.

But the burger has not been immune from criticism.

Genetically modified yeast, a lack of organic ingredients, processed soy, and a high saturated fat and salt content have concerned some critics. And the burger has been criticized by animal rights activists for testing products on rats. Cattle ranchers have also mounted opposition to Impossible Foods and Beyond Meat for selling patties in grocery stores in the same refrigerators as meat.

Nestlé this week announced it would also try its hand at manufacturing a plant-based burger. It will launch the “Incredible Burger” in Europe and the “Awesome Burger” in the US this fall, according to Reuters. The plant-based industry is expected to grow to $10bn in the next five years, according to analysts.

• This article was amended on 4 April 2019 to clarify that the Impossible Whopper is a plant-based burger, but is not vegan.