The Postwar Period and Modern Times: After World War II American-led forces occupied Japan a woman named Miss Appleton was officially placed in charge of supervising the revival of Japan’s shoyu industry. Basic raw materials for shoyu, as well as foods in general and money to buy food were all in precariously short supply.
Shoyu makers had to depend primarily on imported American soybeans allotted by Miss Appleton. Having little knowledge of the traditional methods for making fine shoyu, but wishing to produce a low-cost product quickly and make best use of the available raw materials, she recommended that all producers make quick HVP (chemical) soy sauce instead of the higher-quality fermented product, which would not be ready for a year or more. In 1945 she issued an order that all of Japan’s 8,000 shoyu makers should do as she said or forego their quota of soybeans.
The producers objected and, fortunately, in 1948 Noda Shoyu Co. announced the development of their patented New-style Shoyu No. 2 (Shinshiki Nigo Shoyu), which they again agreed to share with all makers free of charge. This new compromise process, which combined chemical hydrolysis with fermentation, yielded a product which came to be known as semichemical shoyu (shinshiki shoyu), and which has a better odor than plain chemical shoyu.
The quick, new process so impressed Miss Appleton that she permitted allocation of the soybeans to all who used it. In the semichemical process defatted soybean meal was first partially hydrolyzed by dilute (7-8%) hydrochloric acid, then neutralized with sodium hydroxide. Next large amounts of koji, made from wheat bran and flour, were added and the mixture was fermented with osmophilic yeasts for 1-3 months. Still, small amounts of undesirable furfurol and sulfide-like odors not found in fermented shoyu inevitably appeared in the final product.