A coffee processing apparatus (100, 200, 300) is disclosed that comprises at least one of a grinding stage (110) for grinding coffee beans (10) into ground coffee beans (20); and a brewing stage (140) for brewing coffee from ground coffee beans; the coffee processing apparatus further comprising a sensor (150) arranged to sense a total concentration of volatile organic compounds released by said coffee beans or ground coffee beans; and a controller (160) responsive to said sensor and arranged to control said grinding stage and/or said brewing stage as a function of said total concentration. Methods of controlling such a coffee processing apparatus are also disclosed.