A system is provided for detecting cooking utensil-related properties through a solid-surface cooktop, including the presence/absence, removal/placement, and other properties (e.g., size) of a cooking utensil on the cooktop. An energy source heats the contents of a cooking utensil placed on the cooktop; and an optical radiation source is controlled to provide an interrogation scheme for detecting the utensil properties. The utensil property detecting system may be part of a monitoring system for monitoring the properties of the cooking utensil, or may be part of a control system for controlling the energy source based on the detected utensil properties, or both.