Kōsō is a traditional Japanese term that refers to the process of fermentation, particularly in the context of food and beverages. It is essential in creating various products, such as miso, sake, and soy sauce. The fermentation process involves microorganisms like yeast and bacteria, which break down sugars and starches, enhancing flavors and preserving food. In addition to its culinary applications, kōsō is also linked to health benefits. Fermented foods are known to promote gut health and improve digestion due to the presence of probiotics. This practice has been a part of Japanese culture for centuries, emphasizing the importance of natural fermentation in daily life.