What Is Koji
Koji is a sweet, fragrant, cultured grain. Primarily used as the first stage in a multitude of dual stage fermentations. Koji is a cornerstone of Japanese cuisine and is the culture responsible for such ferments as; miso, amazake, sake, rice vinegar, mirin and soy sauce. In 2006 the Brewing Society of Japan recognized Koji as the national mold of Japan. For our purposes we primarily cultivate rice koji and will refer to koji as thus. However, koji may also be cultured on other grains such as barley and soybeans.
In Japan the written history of the "selective cultivation" of koji dates to over 1300 years ago, with a much longer history in China. The koji making process is one of the longest practiced examples of solid state fermentation. Solid state fermentation involves the growth of microorganisms on and within solid organic materials in the absence or near absence of free water. Similar to the process taking place when cultivating mushrooms.
Growing koji is kind of like farming enzymes. As the culture grows into the grain it releases enzymes that help to break down fats, carbohydrates, and proteins. We then utilize these enzymes in the fermentation process allowing for quick work for our microbial partners.