Final answer:
When cooking burgers on a grill, the edges should turn brown before flipping. This indicates the burger is cooked on that side, and flipping will allow for even cooking.
Step-by-step explanation:
When cooking burgers on a grill, a common indicator that the burger is ready to be flipped is when the edges turn brown. This visual cue suggests that the burger has begun to cook through on that side. After flipping, allow the other side to cook until it reaches the desired level of doneness, which can vary depending on personal preference or safety guidelines. For example, the USDA recommends cooking ground beef to an internal temperature of 160°F to ensure harmful bacteria are killed.