The little round spots on the hamburger patty are solidified meat protein called albumin.When a burger is cooked very quickly at high heat—especially from a frozen state on a high-temperature broiler like those used at fast-food restaurants—the natural proteins and moisture inside the meat expand and push out to the surface. When this liquid protein hits the intense heat, it cooks instantly and hardens into small, circular bumps or "freckles". While it can look unusual or unappetizing, it is a normal cooking byproduct and is completely safe to eat.