A capsule-detecting module for a brewing module for preparing a brewed drink from a single-serve capsule, including: an optical sensor, especially a camera, for detecting optical properties of the capsule located in a capsule detection position; a capsule detection window made of a transparent material and arranged between the capsule detection position and the camera; and a module cover that closes an access opening and is designed to be opened and/or removed without using any tools, the side of the capsule detection window facing the capsule detection position being accessible through the access opening when the module cover is open or removed.