The invention provides a measuring device for measuring the acoustic properties, such as acoustic damping and sound velocity in milk, in order to determine milk properties. Said sound velocity in milk depends on temperature and composition. By carrying out, for example by means of a piezo element 12, a reference measurement on vibrations that have been directed by a second piezo element 13 into a wire 10 or the like of known material, which wire 10 is strung in the measuring chamber 1 which is filled with the milk 5 to be tested, the milk temperature can be derived, so that other milk properties, in particular the fat/protein composition, can be determined in a more reliable manner.