TECHNOLOGY FOCUS - BIOLOGY - Preferred Process: The first separation step comprises a mechanical separation step or a centrifugal separation step. The mechanical separation step of first separation step includes a decanting step. The second separation step comprises a mechanical separation step. The mechanical separation step of the second separation stage includes a centrifugal separation step, which is carried out using a disk stack separator. The third stream is subjected to a dewatering step. The dewatering step comprises a mechanical dewatering step, which comprises subjecting the third stream to a filter press. The first separation step comprises a mechanical separation step or a centrifugal separation step. The mechanical separation step of first separation step includes a decanting step. The second separation step comprises a mechanical separation step. The mechanical separation step of the second separation stage includes a centrifugal separation step, which is carried out using a disk stack separator. The third stream is subjected to a dewatering step. The dewatering step comprises a mechanical dewatering step, which comprises subjecting the third stream to a filter press. The process further comprises: drying the third stream, after the dewatering step, to further reduce the moisture content; and formulating the recovered fermentation agent as a feed additive in an animal feed composition, where the fermentation agent comprises less than 2 wt.% of the animal feed composition. The fourth stream is subjected to an evaporation step to produce a syrup. The unfermented organic material is processed into a cake after separation from the stillage. The syrup is sprayed onto the cake, to produce distillers dark grains and solubles (DDGS). The process comprises formulating the recovered fermentation agent as a protein source in a feed material in an animal feed composition, where the fermentation agent comprises more than 2 (preferably 5-40) wt.% of the animal feed composition. Preferred Components: The organic material comprises a fermentable carbohydrate i.e. a cereal grain (e.g. maize, wheat, sorghum and barley), potato or beet molasses. The fermentation agent comprises: fungal cells capable of fermenting the organic material to ethanol; or a yeast, which is of the genus Saccharomyces, preferably the fermentation agent is a yeast. In the protein-containing composition, the yeast comprises 90-99.5 wt.% of the composition, based on the dry weight of the composition. The NSP is present at up to 5 wt.% of the composition. The NSP comprises arabinoxylan (90 wt.%), beta -glucan and/or galactose. Preferred Composition: The protein-containing composition further comprises: sucrose; at least one reducing sugar; at least one mineral; at least one water soluble oligosaccharide; and water.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The third separation stage comprises: a mechanical separator; a disk stack separator. The apparatus further comprises: a dewaterer for dewatering the recovered fermentation agent; and a drier for removing additional moisture from the recovered fermentation agent. EXAMPLE - No suitable example given.