Nuruk is a traditional Korean fermentation starter made from grains, typically wheat or barley, that have been allowed to mold. This process creates a natural source of yeast and enzymes, which are essential for fermenting various foods and beverages, particularly makgeolli, a type of rice wine. The preparation of nuruk involves mixing the grains with water and allowing them to ferment in a warm environment. Once dried, it can be ground into a powder and used to initiate fermentation in other recipes. Nuruk plays a crucial role in Korean culinary traditions, contributing to the unique flavors and textures of fermented products.