Protein
Japanese: タンパク質
A macromolecule composed of amino acid chains. In fermentation, it is broken down by proteases to release amino acids—the source of umami.
Protein is a macromolecule made of tens to thousands of amino acids linked together. Soybeans contain about 35% protein, serving as the raw material for umami in miso.
Proteases secreted by koji mold cleave this protein into peptides and free amino acids. Glutamic acid, aspartic acid—the essence of umami is born from this 'dismantling' of protein.
Raw soybeans don't taste umami-rich. But after months as miso, the same soybeans have transformed into a concentrated mass of deep flavor. Protein realizes its full gustatory potential only through the time-based craft of fermentation.