Peptides

Peptides are compounds formed when two or more amino acids are joined together, and they are produced during the breakdown of proteins. They form when amino acids link to one another through a chemical bond known as a peptide bond. In sake, yeast and other microorganisms break down sugars and proteins during fermentation, producing peptides and amino acids. These substances are an important influence on the flavor and umami of sake. Peptides in particular contribute to drinkability and body (koku, a sense of richness and depth), making them an important component of sake's flavor.