Producing alcohol and/or solvent from a biomass feedstock, comprises (a) contacting and heating the biomass feedstock with water and an acidic or basic compound, (b) contacting the pretreated substrate with cellulase enzyme and a wash liquid stream, (c) extracting a portion of the solid material contained in the hydrolyzate to obtain a solid material depleted hydrolyzate and a solid material enriched stream, (d) washing the solid material enriched stream with a liquid stream, and (e) carrying out alcoholic fermentation of the solid material depleted hydrolyzate using a microorganism. Producing alcohol and/or solvent from a biomass feedstock, comprises (a) carrying out a pretreatment step by contacting and heating the biomass feedstock with water and an acidic or basic compound to obtain a pretreated substrate, (b) contacting the pretreated substrate with at least one cellulase enzyme and a wash liquid stream obtained in step (d) to obtain a hydrolyzate comprising a solid material and a liquid phase containing sugars, (c) extracting at least a portion of the solid material contained in the hydrolyzate to obtain a solid material depleted hydrolyzate and a solid material enriched stream, (d) washing the solid material enriched stream with a liquid stream to obtain wash liquid stream, where the wash liquid stream is recycled to step (b), (e) carrying out an alcoholic fermentation of the solid material depleted hydrolyzate obtained in the step (c) using a microorganism to produce a fermented wine, and (f) separating the fermented wine to obtain at least one purified stream comprising an alcohol or a solvent and at least one stillage stream.
