https://www.cnet.com/news/burger-kings-meat-free-impossible-whopper-tastes-real-thats-no-april-fools-joke/

The remarkable thing was how unremarkable they were: Nothing gives away the fact that this Whopper contains a different main ingredient.

The patties supplied to Burger King will be based on Impossible's new 2.0 formulation that was announced at CES in January, 2019. Among other upgrades, this formulation holds up better in restaurant environments like sitting in hot holding trays or the 6-inch drop at the end of the conveyor that grills the patty for exactly 2 minutes and 35 seconds at 630 degrees.