A process of treating organic waste such as food wastes for anaerobic digestion including preparing a waste-slurry from organic waste such as food wastes, transferring the organic waste-slurry to a paddle pulper/finisher, processing the waste-slurry in the paddle pulper/finisher which reduces the particle size of the solids in the waste slurry and separates the waste slurry into a pulp slurry and pomace, and processing the pulp slurry in an anaerobic digester for the production of methane gas fertilizer and soil amendments. In a further process, the organic waste is slurried by dumping the organic waste in a slurry tank, adding a liquid and mechanically mixing the organic waste and liquid until consistent slurry is attained. In a still further process, the slurry from the slurry tank is processed by forming a macerator-slurry in an inline macerator unit which removes heavy solids and cuts other solids into smaller sizes which can be transferred by a slurry pump.