TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The method further comprises: preparing the biomass feedstock before pretreating, by physically treating the biomass feedstock to reduce the bulk density of the feedstock; contacting the biomass feedstock with a microorganism or an enzyme; and subjecting the biomass feedstock to enzymatic hydrolysis. The physically treating: opens up the pretreated biomass feedstock; and exposes internal fibers of the feedstock. The physically treating or preparing the biomass feedstock comprises: shearing the feedstock; and subjecting the feedstock to at least one of stone grinding, mechanical ripping or tearing, pin grinding, milling and air attrition milling. The pretreating comprises irradiating with ionizing radiation, preferably with an electron beam. The pretreatment increases the brittleness of the feedstock. Preferred Components: The physically treated material has an uncompressed bulk density of less than 0.6 g/cm3. The physically treated material includes fibers having a length/diameter (UD) ratio of at least 5. The biomass feedstock comprises a cellulosic or lignocellulosic material, which is paper, paper product, paper waste, wood, particle board, sawdust, agricultural waste, sewage, silage, grasses, rice hull, bagasse, cotton, jute, hemp, flax, bamboo, sisal, abaca, straw, corn cobs, corn stover, switchgrass, alfalfa, hay, coconut hair, seaweed and/or algae. EXAMPLE - A 1500 pound skid of virgin bleached white kraft board was folded flat and then fed into a Flinchbaugh shredder at 15-20 pounds/hour. The shredder was equipped with two 12 inch rotary blades, two fixed blades and a 0.30 inch discharge screen. The gap between the rotary and fixed blades was adjusted to 0.10 inch. The output from the shredder (confetti-like material) was fed to a Munson rotary knife cutter. The gap between the rotary and fixed blades was set to 0.020 inch. The rotary knife cutter sheared the confetti-like pieces across the knife-edges. The material resulting from the first shearing was fed back into the same setup and this material was sheared for two more times. The resulting thrice Sheared fibrous material had a Brunauer, Emmett and Teller surface area of 1.6897 m2/g plus minus 0.0155 m2/g, porosity of 87.7163% and bulk density of 0.1448 g/ml. Approximately 1 lb of water was sprayed onto each 10 lb of fibrous material. The fibrous material was densified using a California Pellet Mill 1100 operating at 75 degrees C. Densified pellets were obtained having a bulk density of 7-15 lb/ft3. The densified pellets were placed in a glass ampule having a maximum capacity of 250 ml. The glass ampoule was evacuated under high vacuum (10-5 torr) for 30 minutes and then back-filled with argon gas. The ampule was sealed under argon. The pellets in the ampule were irradiated with gamma radiation for 3 hours at a dose rate of about 1 Mrad/hour to provide an irradiated material in which the cellulose had a lower molecular weight than the fibrous kraft starting material.