The most mysterious ingredient use to make sake is koji. What is it? Why is it so important? What does it contribute to sake? Well, these are all important questions we will address here. Koji is a general term that is almost always used as a specific term by those talking about sake. In the general case koji is some kind of substrate with some kind of mold growing on it. How’s that for a technical description. Koji used for making sake is, in most cases, yellow koji consisting of Aspergillus Oryzae growing on milled rice.
Yellow koji is also used for making Shochu, a distilled beverage, but has been mostly replaced by other forms of mold and substrate. The two most common molds now used for koji in the production of shochu are Aspergillus Kawachi (white) and Aspergillus Awamori (black). In the general case the substrates also very quite a bit. Substrates of buckwheat, sweet potato, barley and rice are common. Rice is always the substrate used for sake. Continue reading “Koji What?”