A method is proposed for ascertaining the quality and/or the composition of milk, in particular during a milking operation, in which the fill level of the milk in a chamber is determined. After the fill level of the milk in the chamber has been determined, the milk is irradiated using at least one radiation of a predefined wavelength. The intensity of the reflected radiation is measured. The fill level and the intensity of the reflected radiation represent a value pair. Characteristic values are stored in a memory. A characteristic value is assigned to the ascertained value pair. A statement about the quality and/or the composition of the milk can be made from the characteristic value thus ascertained.
