NOVELTY - Composition produced by a process for the treatment of ligno-cellulosic biomass comprising: (a) soaking a ligno-cellulosic biomass feedstock in vapor and/or liquid water to create a soaked biomass containing a dry content and a first liquid; (b) separating at least a portion of the first liquid from the soaked biomass to create a first liquid stream and a first solid stream; (c) steam exploding the first solid stream to create a steam exploded stream comprising solids and a second liquid; (d) adding the first liquid and the second liquid to create the composition, is claimed.    USE - The composition is useful as ethanol and other biofuels.    ADVANTAGE - The composition is prepared in a simple and cost-effective manner. The composition controls the xylose ratio of pretreated biomass.    DETAILED DESCRIPTION - Composition produced by a process for the treatment of ligno-cellulosic biomass comprising: (a) soaking a ligno-cellulosic biomass feedstock in vapor and/or liquid water at a first temperature and for a first time corresponding to a first severity factor to create a soaked biomass containing a dry content and a first liquid; (b) separating at least a portion of the first liquid from the soaked biomass to create a first liquid stream and a first solid stream, where the first solid stream comprises the soaked biomass; (c) steam exploding the first solid stream at a second temperature for a second time corresponding to a second severity factor to create a steam exploded stream comprising solids and a second liquid; (d) adding at least a fraction of the first liquid and a fraction of the second liquid to create the composition, is claimed, where the sum of first severity factor and second severity factor is 5000-17000, the ratio between xylooligomers content and the sum of xylose content and xylooligomers content is greater than 0.5, and the ratio between the sum of xylose content and xylooligomers content and solubilized xylans content is greater than 0.35.