We focus in this paper on the bleeding phenomenon and its kinetics at the scale of cement paste.Our experimental results on simple systems suggest that bleeding cannot be simply considered as the consolidation of a porous material but is of an obvious heterogeneous nature leading to the formation of water extraction channels or preferred paths within the paste.As a consequence, its kinetics can be divided into three regimes: a dormant period (which could, if fully understood, be of major interest from an industrial point of view), an accelerating period (during which the apparent permeability of the paste increases due to the formation and percolation of water extraction channels) and a consolidation regime (during which the permeability of the sample decreases because of the water extraction itself until gravity is not able to further consolidate the sample and extract any additional water).Only the latter had been observed until now in literature.