NOVELTY - Method for producing fermentable sugars from cellulosic biomass, involves providing a feedstock comprising cellulosic biomass, extracting the feedstock with an extraction solution, separating at least a portion of the cellulose-rich solids from the extract liquor, removing a portion of glucan contained in the washed cellulose-rich solids, co-hydrolyzing the glucose oligomers and the hemicellulose oligomers, with enzymes or an acid catalyst, and recovering the glucose and hemicellulose monomers as fermentable sugars.    USE - The method is useful for producing fermentable sugars from cellulosic biomass (claimed).    ADVANTAGE - The method is cost-effective to perform.    DETAILED DESCRIPTION - Method for producing fermentable sugars from cellulosic biomass, involves (a) (i) providing a feedstock comprising cellulosic biomass, (ii) extracting the feedstock with an extraction solution including steam and/or hot water under effective extraction conditions to produce an extract liquor containing hemicellulose oligomers, dissolved lignin, and cellulose-rich solids, (iii) separating at least a portion of the cellulose-rich solids from the extract liquor, to produce washed cellulose-rich solids, (iv) removing a portion of glucan contained in the washed cellulose-rich solids by contacting the washed cellulose-rich solids with a liquefaction-focused blend of enzymes, to release glucose oligomers, (v) co-hydrolyzing the glucose oligomers and the hemicellulose oligomers, with enzymes or an acid catalyst, to produce glucose and hemicellulose monomers, and (vi) recovering the glucose and hemicellulose monomers as fermentable sugars, or (b) (i) performing above-mentioned steps (a) (i)-(a) (iv), (ii) hydrolyzing the glucose oligomers with a first hydrolysis catalyst, to produce glucose, (iii) hydrolyzing the hemicellulose oligomers with a second hydrolysis catalyst, to produce hemicellulose monomers, and (iv) recovering the glucose and hemicellulose monomers, individually or in combination, as fermentable sugars.