Shio koji — koji mixed with salt to produce a wet paste — is one of the most practically useful applications of the koji enzyme principle. The paste is applied directly to protein as a marinade: the koji's proteases and amylases attack the protein surface, tenderising the meat and producing free amino acids (for umami) and simple sugars (for Maillard browning enhancement). A 24–48 hour shio koji marinade produces results in texture and Maillard browning that would otherwise require 3x the cooking temperature.
- **The preparation:** Dry koji (previously made) + salt + water — combined to a paste. [VERIFY] Noma's ratio. - **Application:** The paste spread directly on the protein surface. The enzyme contact is what matters — the paste must touch the protein. - **Time:** 24–48 hours in the refrigerator. The enzyme activity is slower at low temperatures but the slow activity produces more controlled, even results than room temperature application. - **The browning enhancement:** When the shio koji-marinated protein is cooked at high heat, the amino acids and simple sugars produced by the enzyme activity participate in Maillard reactions far more readily than untreated protein — the surface browns faster, deeper, and with more complex flavour compounds. - **Applications:** Fish, chicken, pork — all benefit. Vegetable applications (shio koji on cucumber, carrot) produce a mild, pleasant pickle-like transformation.
Noma Fermentation