Yellow koji mold (Kikoji-kin)

Yellow koji mold (kikoji-kin, 黄麹菌) is a type of koji mold, a microorganism whose spores are yellow, yellow-green, or yellow-brown in color. It is used in the production of a variety of fermented foods, including sake. In sake brewing in particular, it converts starch into sugar, and alcohol is then produced in the subsequent fermentation process. Yellow koji mold also plays an important role in making miso and soy sauce, where it is essential for bringing out flavor and aroma. Its use adds a distinctive flavor and umami to the finished product.