A Valley-type beater for beating pulps under standardized laboratory conditions. Pulp fibers in aqueous suspension pass between a set of stationary and rotating metal bars under controlled conditions of rate and pressure. The beater may be used to produce pulp samples at increasing degrees of beating, from free to wet, which may then be formed into laboratory hand sheets for physical property measurements. Thus it is possible to assess the paper making potential of pulps without the necessity of full-scale trials.