The present invention provides for a method for deconstructing a post-consumer cellulosic composition comprising: (a) providing a soiled post-consumer cellulosic composition previously subjected to a high temperature and high pressure process, (b) introducing a cellulase to the soiled post-consumer cellulosic composition such that a sugar is produced, (c) optionally separating the sugar from the soiled post-consumer cellulosic composition, (d) optionally culturing a microbial strain in a culture medium using the sugar produced from (b) introducing step as a carbon source such that a biofuel is produced, and (e) optionally separating the biofuel produced in the (d) culturing step from the culture medium； and novel compositions thereof.
