A hogging, sometimes known as reducing, apparatus for reducing wood waste into hog fuel, though some embodiments may also be used for reducing other materials including demolition timber, demolition masonry, mild steel scrap (thin sections), soft metal scrap, recycled cans, recycled glass, recycled plastic, soft rocks, occasionally hard rocks, recycled roading and asphalt, old tyres, and certain green garden waste. The apparatus includes a drum (40) inclined to the horizontal and into which raw material can be fed at its upper end. Rotation of the drum (40) assists driving raw material towards reducing elements (45) positioned at an angle near its (40) lower end. Screening apertures (41) allow sufficiently comminuted material to pass therethrough for removal. Optional features include internal agitators (60) for improving processing and screening, assisted drying of raw material by motor exhaust (71), and initial pre-screening of foreign material.