A method of producing a concentrated sugar solution from biomass, the method comprising: a) delignifying biomass comprising the substeps of i) contacting with water and at least one nucleophilic base, a biomass comprising lignin and having a glucan/xylan weight ratio G 1 /X 1 to form a biomass slurry having a pH of 12.5 to 13.0, wherein the at least one nucleophilic base comprises a water-soluble metal hydroxide; and ii) maintaining the biomass slurry under reaction conditions such that the slurry attains a pH of 9.5 to 10.0 and has a glucan/xylan weight ratio G 2 /X 2 within 15% of the value of G 1 /X 1, and wherein the slurry comprises a lignin-containing liquid fraction and a solid fraction comprising a polysaccharide-enriched biomass; wherein G 1 and G 2 are grams of glucan per 100 grams of biomass and biomass slurry respectively, and X 1 and X 2 are grams of xylan per 100 grams of biomass and biomass slurry respectively; and b) contacting with a saccharification enzyme consortium an aqueous suspension of at least a portion of the solid fraction of the polysaccharide-enriched biomass, the solid fraction of the polysaccharide-enriched biomass being 13 weight percent to 30 weight percent of the aqueous suspension, at reaction conditions sufficient to produce a saccharification product comprising at least 7 percent by weight sugars, based on the total weight of the saccharification product, in 24 hours of contact with the saccharification enzyme consortium; wherein after delignifying, an additive is added, said additive being selected from the group consisting of polyethylene glycols, fatty acid esters, fatty acid ethoxylates, nonionic surfactants derived from polyethoxylated sorbitan and a fatty acid, sodium lauriminodipropionate, sodium cocoamphoacetate, sodium tridecyl ether sulfate, and a combination of these, such that enzyme loading of the saccharification enzyme consortium is reduced relative to enzyme loading of the saccharification enzyme consortium when none of the additives is added. a) delignifying biomass comprising the substeps of i) contacting with water and at least one nucleophilic base, a biomass comprising lignin and having a glucan/xylan weight ratio G 1 /X 1 to form a biomass slurry having a pH of 12.5 to 13.0, wherein the at least one nucleophilic base comprises a water-soluble metal hydroxide; and ii) maintaining the biomass slurry under reaction conditions such that the slurry attains a pH of 9.5 to 10.0 and has a glucan/xylan weight ratio G 2 /X 2 within 15% of the value of G 1 /X 1, and wherein the slurry comprises a lignin-containing liquid fraction and a solid fraction comprising a polysaccharide-enriched biomass; wherein G 1 and G 2 are grams of glucan per 100 grams of biomass and biomass slurry respectively, and X 1 and X 2 are grams of xylan per 100 grams of biomass and biomass slurry respectively; and i) contacting with water and at least one nucleophilic base, a biomass comprising lignin and having a glucan/xylan weight ratio G 1 /X 1 to form a biomass slurry having a pH of 12.5 to 13.0, wherein the at least one nucleophilic base comprises a water-soluble metal hydroxide; and ii) maintaining the biomass slurry under reaction conditions such that the slurry attains a pH of 9.5 to 10.0 and has a glucan/xylan weight ratio G 2 /X 2 within 15% of the value of G 1 /X 1, and wherein the slurry comprises a lignin-containing liquid fraction and a solid fraction comprising a polysaccharide-enriched biomass; b) contacting with a saccharification enzyme consortium an aqueous suspension of at least a portion of the solid fraction of the polysaccharide-enriched biomass, the solid fraction of the polysaccharide-enriched biomass being 13 weight percent to 30 weight percent of the aqueous suspension, at reaction conditions sufficient to produce a saccharification product comprising at least 7 percent by weight sugars, based on the total weight of the saccharification product, in 24 hours of contact with the saccharification enzyme consortium;