The phrase describes the necessary duration of exposure to intense heat on a grill to bring a cut of London broil beef to an internal temperature indicative of medium-rare doneness. This cooking level typically corresponds to an internal temperature of approximately 130-135F (54-57C) when measured with a meat thermometer. For instance, asking “How long to grill London broil for medium rare?” implies seeking the specific time needed for achieving that desired internal temperature.
Achieving medium-rare doneness is often preferred due to the resulting tenderness and enhanced flavor profile of the meat. Overcooking London broil can lead to a tough and less palatable result, making precise timing essential. Historically, grilling has been a method for cooking meat quickly over direct heat, requiring careful monitoring to prevent burning or uneven cooking. The specific duration depends on the grill’s heat, the steak’s thickness, and the desired level of doneness.