Beverage preparation machine with capsule identification

A machine (1) for preparing and dispensing a beverage (2), such as tea, coffee, chocolate hot, chocolate cold, milk, soup or infant food, where the machine comprises a capsule identification module (8) for identifying the type of capsule (3) inserted in the machine (1), the capsule identification module (8) comprising: a light source (82) for emitting light to the capsule (3); the light source is used for illuminating at least one part of the surface of the capsule (3); and an optical sensor (81) for sensing an optical property of at least a portion of the surface of the capsule (3); and wherein the capsule identification module (8) is configured to: determine a correction value for an optical property of at least a portion of the surface of the capsule (3) by sensing the optical property while said light source (82) is turned off; determining at least one sample value of an optical property of at least a portion of the surface of the capsule (3) by sensing the optical property while the light source (82) is