NOVELTY - Processing municipal solid waste (MSW), comprises: (i) providing MSW at a non-water content of 5-40% and at a temperature of 45-75 degrees C; (ii) enzymatically hydrolyzing the biodegradable parts of the MSW concurrently with a microbial fermentation at a temperature of 45-75 degrees C resulting in liquefaction of biodegradable parts of the waste and accumulation of microbial metabolites; followed by (iii) sorting of the liquefied, biodegradable parts of the waste to produce a bioliquid comprising dissolved volatile solids; and followed by (iv) anaerobic digestion of the bioliquid to produce biomethane.    USE - The method is useful for processing MSW using enzymatic hydrolysis and microbial fermentation, to produce methane (claimed), where the MSW includes domestic household wastes, wastes from restaurants and food processing facilities, and wastes from office buildings.    ADVANTAGE - The simple method is capable of processing MSW in a rapid and economical manner.    DETAILED DESCRIPTION - Processing municipal solid waste (MSW), comprises: (i) providing MSW at a non-water content of 5-40% and at a temperature of 45-75 degrees C; (ii) enzymatically hydrolyzing the biodegradable parts of the MSW concurrently with a microbial fermentation at a temperature of 45-75 degrees C resulting in liquefaction of biodegradable parts of the waste and accumulation of microbial metabolites; followed by (iii) sorting of the liquefied, biodegradable parts of the waste from non-biodegradable solids to produce a bioliquid comprising dissolved volatile solids of which comprise at least 25 wt.% of any combination of acetate, butyrate, ethanol, formate, lactate and/or propionate; and followed by (iv) anaerobic digestion of the bioliquid to produce biomethane. An INDEPENDENT CLAIM is included for an organic liquid biomethane substrate produced by enzymatic hydrolysis and microbial fermentation of MSW comprising at least 40 wt.% of the non-water content exists as dissolved volatile solids, which dissolved volatile solids comprise at least 25 wt.% of any combination of acetate, butyrate, ethanol, formate, lactate and/or propionate.