When is a burger patty considered done based on the appearance of its juice?

A burger patty is considered done when the juices run clear. This appearance indicates that the meat has reached a safe internal temperature, which typically ensures that any harmful bacteria are killed and that the burger is safe to eat. Clear juices mean that the protein has cooked through sufficiently, leading to the evaporation of any reddish or pink coloration that might be present in undercooked meat.

The appearance of red or pink juices suggests that the meat may not be fully cooked, which can pose a risk of foodborne illness. Brown juices can also be an indication of doneness, but clear juices are the most reliable indicator that the meat is safe. Thus, clear juices represent the ideal sign of a burger that has been cooked to the appropriate level of doneness.