Molecular Microbiology Research, 2025, Vol.15, No.2, 45-58 http://microbescipublisher.com/index.php/mmr 46 fermentation conditions, and establishing objective flavor and quality evaluation indicators, traditional soy sauce brewing is bursting with new vitality (An et al., 2023). In this context, this study takes the traditional sauce making technique of Yuyue as an example to systematically explore its process evolution, microbial fermentation system, flavor formation mechanism, process optimization and intelligent path, quality evaluation standards and food safety control, analyze the practical effects of the integration of tradition and innovation, and look forward to the future development direction. The research aims to provide scientific basis and typical demonstration for the modernization and upgrading of the traditional fermented food industry. 2 The Origin and Evolution of Traditional Sauce Making Techniques of Fish Leap 2.1 Historical origin: inheritance of the legacy of Northern Song Dynasty The brewing technique of Yuyue soy sauce is said to originate in the Northern Song Dynasty, and corresponds to the method of making sauces promoted by historical figures such as Qin Guan in Lishui. This ancient method takes natural fermentation as the core, and relies on microorganisms that naturally exist in the environment to make koji and ferment, without using artificial inoculated purebred bacteria. During the Yuan, Ming and Qing dynasties, folk experience in hand-made soy sauce was accumulated continuously and passed down from region to region. The ancient recipes and processes of Yuyue Soy Sauce are the crystallization of this historical heritage. In 1919, Ying Desheng founded the "Desheng Sauce Garden" in Lishui, marking the beginning of the Yuyue brand. The establishment of Desheng Sauce Garden not only inherited the traditional soybean skills, but also introduced the advanced management concepts at that time, realizing the transition from manual skills to commercial production. Since then, several generations of descendants have abide by the ancient methods and strive for excellence, making Yuyue Soy Sauce famous in the local area. The origin of the fish leap technique reflects the context of Chinese soy sauce brewing from the interests of court literati to the development of folk handicrafts, and also demonstrates the tenacious vitality of intangible cultural heritage techniques after dynasties. 2.2 Craft features: traditional brewing process Yuyue’s traditional sauce making technique has strict and sophisticated process, representing the essence of the ancient methods of Jiangnan sauce garden. Its main raw materials are soybeans and flour. The brewing process includes soaking beans, steaming beans in wooden barrels, cooling, natural inoculation of mold, hand-made koji, pressing koji mash (that is, mixing the cultivated koji with cooked salt water to form sauce mash), long-term fermentation of open-air sun-drying, pressing sauce, torture and concentration, and sealing and aging of the jar. Among them, "three fermentation, second immersion, and one pressing" is the unique process key of fish leaping soy sauce, which means supplementing nutrients and prolonging fermentation in stages during the long fermentation process to give full play to the role of microbials (Duan et al., 2010). It is particularly worth mentioning that the open-air fermentation process: the fish leaps in large outdoor tanks for sun exposure for at least 180 days. This open long-term fermentation allows Aspergillus, yeast, bacteria, etc. to reproduce and metabolize in different seasons, giving the soy sauce a rich and mellow flavor (Figure 1) (Yang et al., 2017). After pressing the raw butter, Yuyue Soy Sauce insists on "frying soy sauce" on low heat, that is, heat and concentrate the soy sauce to a certain baume, which not only kills the remaining bacteria to ensure safety, but also adds the sauce color and aroma through the Melade reaction. The ancient fish-leap craftsmanship has strict requirements for every detail, and the brewing master needs to judge the temperature and timing based on experience. Its products have traditional characteristics of rich sauce flavor, salty, fresh and palatable, and reddish brown and transparent color, which are very popular among consumers. 2.3 Modern inheritance and innovation Entering the 21st century, the old Yuyue Soy Sauce factory once faced the challenge of market competition and decline in efficiency. In 2006, with the support of local governments, Yuyue carried out enterprise restructuring, and the tenth-generation successor Chen Xudong took over the sauce garden. He adheres to the concept of "not seeking the top 100, but seeking the top 100 years", insists that the core of ancient brewing remains unchanged,
RkJQdWJsaXNoZXIy MjQ4ODYzNA==