A cooling system (10) for cooling a flow of milk comprises a first and a second refrigeration system (11, 12) a first and a second intermediate coolant circulating system (13, 14) and a line manifold interconnectable between the first and second intermediate coolant circulating systems, wherein coolant in the first intermediate coolant circulating system is in heat exchange connection with the first refrigeration system in a first heat exchange section (15) and coolant in the second intermediate coolant circulating system is in heat exchange connection with the second refrigeration system in a second heat exchange section (16). The cooling system is reconfigurable between first operation configuration providing two-stage cooling of the flow of milk and a second operation configuration providing one-stage cooling of the flow of milk.