A method for processing brewery waste that includes receiving spent grain, low strength wastewater and high strength wastewater. The spent grain, low strength wastewater and high strength wastewater is processed with a plug flow anaerobic digester to produce a first output. A portion of the first output is processed with an upflow anaerobic sludge blanket digester to produce a second output. A portion of the second output is processed with a fixed-film anaerobic digester to produce a third output.