The process for the hydrolysis of ligno-cellulosic biomass comprises the steps of A) Contacting a ligno-cellulosic feedstock, the feedstock comprised of biomass having a dry content and water with at least a portion of a solvent, the solvent comprised of water soluble hydrolyzed species; wherein at least some of the water soluble hydrolyzed species are the same as the water soluble hydrolyzed species obtainable from the hydrolysis of the biomass in the feedstock; B) maintaining the contact between the feedstock of the feedstock stream and the solvent at a temperature in the range of 20° C. to 200° C. for a time in the range of 5 minutes to 72 hours to create a hydrolyzed product from the biomass in the feedstock.