The present invention relates to a rotary milking parlour capable of selecting milk of an unacceptable quality and to a method using such a rotary milking parlour. The milking parlour comprises a rotary platform, plurality of milking stalls arranged on the rotary platform, a common milk line (27) conducting milk from several milking stalls to a common milk tank, a local milk receiver (24) for each milking stall and a valve member (26) controlling the milk flow from the local milk receiver (24) to the common milk line (27). The valve members (26) are controlled such that all milk of acceptable quality from the local milk receiver (26) is discharged, via the common milk line (27), to a common milk tank before milk of unacceptable quality is discharged from the local milk receivers (26) to the common milk line (27) during a milking period in the milking parlour between two consecutive washing processes of the common milk line (27).
