For thousands of years, we’ve relied on animals to turn plants into meat. Steaks, burgers, and chicken are staples of the American diet. The sustainable food movement that gave rise to grass-fed beef and free-range chicken is now going a step further—a big step further—with the introduction of plant-based, mass-market solutions to replace animal protein. Are these new protein sources poised to transform the global food system? Will laboratory-grown meat be the next solution that will sate the world’s appetite for animal protein? Or is there no substitute for a sizzling slab of beef for the true meat lover?