It is created by the "Maillard reaction", which takes place around two to three months after the brewing process commences. The "Maillard reaction" is quite simply a non-enzymatic browning reaction in which amino acids (proteins) and reducing carbohydrates (sugar) are converted into new compounds. This chemical phenomenon was named after the French biochemist, Louis Camille Maillard (1878-1936), who discovered it in 1912, analysed it and conducted experiments with it. Naturally brewed Kikkoman soy sauce should always be kept tightly sealed and stored in a cool place after opening so that its characteristic colour and incomparable aroma remain intact.