Abstract: A method of processing spent grains by removing suspended solids from the spent grains to produce a stream low in suspended solids, directing the stream low in suspended solids to an anaerobic digester, converting at least some soluble compounds to biogas, and producing a biogas. A method of processing spent grain, by separating a first stream consisting of spent grains into a second stream and a third stream wherein the second stream contains a majority of suspended solids, separating the third stream into a fourth stream and a fifth stream wherein the fifth stream is lower in suspended solids than the fourth stream, directing the fifth stream to an anaerobic digester, and converting at least some organic compounds to a biogas. A method of fermenting a grain product.

Abstract: A protein product recovered from a fermentation process including a protein content of 45.0% or more calculated by weight of dry matter, a glycerol content of 1.0% or less calculated by weight of dry matter, and a mineral nutrient content of 6.0% or less calculated by weight of dry matter. A method for recovering a protein product by heating fermentation stillage to 200 degrees F.-350 degrees F., altering the physicochemical properties of the stillage to enable facile separation of the stillage, and separating a phase enriched in protein. Protein products, protein paste, high protein meal, and proteinaceous agglomerates recovered and formed.