Miso has a full spectrum of flavors and textures but all miso can be simplified into three distinct elements: Ingredients, Taste, and Color. Miso types vary depending upon the environment, climate, water quality and even the storehouse. Koji, an Aspergillus Oryzae fungus culture made with grains or beans, is the essential and most foundational link in the production of miso.
These are the three main types of koji used for fermenting soybeans:
1) Rice Miso: made by adding rice koji into soybeans
2) Barley Miso: made by adding barley koji into soybeans.
3) Soy Miso: has only soybeans as its main ingredient.
There are also mixed koji varieties, which are combinations of soy, grain, and koji.
Depending on its color at the time of completion, miso is divided into Red Miso, Light-colored Miso, or White Miso color types. The color of miso is determined by a variety of facts, from soybean and koji variety used to whether or not the miso was stirred during fermentation process.
Another reason for different degrees of color in miso is due to the “Maillard reaction,” which happens during fermentation and maturation process. Maillard reactions occur when the amino acid, mainly from the soybeans, reacts with a sugar turning to brownish color. Even after miso becomes a completed product, the maturation process continues, making the color darker.
