What are the steps involved in making koji?

The process of making koji involves several key steps that are critical for the growth of the koji mold, Aspergillus oryzae, on steamed rice. The first step, cooling, is essential after the rice has been steamed to bring the temperature down to one that is suitable for mold growth. This step prevents the rice from being too hot, which could hinder the development of the mold.

Next, spreading the cooled steamed rice is crucial as it allows for even distribution and appropriate airflow, which is vital for the koji mold to grow effectively. When the rice is spread out, it provides an ideal environment for the mold to start its growth process.

The following step is the initial growth of the koji mold. During this phase, the mold starts colonizing the rice, breaking down the starches into sugars, which are essential for fermentation in sake production.

The last step in this process is stopping the growth of the koji mold when it reaches the desired level of development. This is typically done by controlling the environment, often through cooling or drying, which ensures that the koji retains its desired characteristics for producing sake.

These steps highlight the importance of temperature and environment in koji making, and understanding this process is essential for anyone interested in the production of