This chapter explains that there are major differences between the saccharification process in traditional food preparation of Western countries and that of the Orient. Shoyu is the Japanese name for soy sauce, a popular liquid condiment used in oriental cuisine. Many varieties of shoyu are produced in Japan and other oriental countries. Japanese-fermented shoyu of the koikuchi type involves five main processes—the treatment of raw materials, the making of koji, the making and aging of mash, pressing, and refining. Fifty years ago, only whole soybeans were used as the raw material for shoyu. The color and flavor of shoyu are very closely related, as both are affected by the aging of mash and the pasteurization of raw shoyu. The color of shoyu is an important attribute to Japanese dishes although it has become lighter in recent years. Using a multivariate analysis, Tanaka indicated that among the factors by which preference for a given shoyu was formed, its chemical composition as a whole contributed only 46.3%. More than 20 Japanese investigators had isolated about 130 flavor compounds from fermented shoyu by the time Goto first introduced the gas chromatography mass spectrometry (GCMS) method into this area of research in 1973, adding six new volatile compounds using this method. The precise mixture of soybeans and wheat used as the raw materials in shoyu production is the result of technological know-how developed over hundreds of years.