A method of pulping wastepaper includes providing a pulping vessel with a rotor and at least one flow sensor to measure slurry flow within the pulping vessel. The pulping vessel is charged a slurry (wastepaper and water), the amounts of wastepaper and water being such that the slurry has consistency in the range of from 10% to 30%. The wastepaper charge in the pulping vessel is pulped at a pre-selected power level while monitoring poloidal slurry flow; water may be added when the poloidal flow falls below a predetermined lower threshold flow value to reduce viscosity and restore poloidal flow within the pulping vessel. Doppler velocimetry is a preferred method of monitoring pulp flow. In a particularly preferred construction the rotor has a variable power drive. The inventive method is especially useful for making high quality, high brightness furnishes from wastepaper which varies from batch to batch.