A method, system and machine for cold processing extruded starch-containing pellets by cold particle size reducing pellets of a size greater than a particle size reduction setting size enabling particle size reduction to be performed without compacting or compression any size reduced particle while doing so without heating them during particle size reduction thereby preserving their pores, internal liquid absorbing voids and starch matrix optimizing granular absorbent performance. Such a method, system and machine is selectively controllable enabling not only control of how many and a ratio of fines produced relative to the final product providing real time control of fines production but also is able to provide particle size distribution control as well. A preferred particle size reduction machine is a roll granulator that breaks larger size pellets into smaller sized particles and/or fines without compressing or compacting them with the spacing between the rolls selectively variably in a manner that regulates how much of different sized particles and/or particles falling within certain size ranges are produced advantageously enabling real time control of particle size distribution to be achieved during extruder line operation.