Caseose is a product of the digestion of casein, the main protein in milk and cheese, formed when digestive enzymes break the protein into peptides during its passage through the gut. The term belongs to older biochemical vocabulary describing intermediate protein digestion products before they are reduced to amino acids. In cheese science, related proteolysis during ripening generates the peptides and amino acids behind flavour development, from savoury notes to bitterness when breakdown goes too far. Understanding casein digestion matters for infant formula design, where protein hydrolysates are tailored for digestibility, and for managing milk protein allergies.