Our Processes


At Rice Culture, we make everything by hand - the traditional way!

Koji and miso are not really made by humans; it is the works of numerous microbes including Koji (Aspergillus oryzae), salt tolerant lactobacillus and yeast and every batch is different. It is the role of us humans to monitor and carefully adjust the environment accordingly so they can perform at their best. And we are very good at this as we as moms are very experienced at monitoring the well-being of our babies!

Here is a glimpse of how we make our koji and miso.


We soak rice in water overnight and then steam using Waseiro (Japanese steamer) made from Hinoki (Japanese cypress). Waseiro works really well to achieve the perfect moisture level in the rice. Steaming rice with Waseiro

We then cool the rice and inoculate with Tane Koji (Koji spores). 

The inoculated rice is then kept in a warm and humid environment for 40-48 hours. This is when the skill of the Koji makers count as Koji can easily heat up to over 50 degrees when they are active and thriving. We need to make sure they are warm and comfortable but not overheat as Koji cannot tolerate heat.

This is a very happy batch of Koji ready to be made into miso and other amazing fermented products! 


Once the Koji is ready, we prepare the soybeans.

We soak in water overnight and cook for over 3 hours until the soybeans are tender.

 The cooked soybeans are then cooled and mixed with Koji and salt.  

The mixture is then mashed and fermented for one months to many years (our oldest batch is now over 9 years old) depending on the varieties. The simple three ingredients - rice, soybeans and salt are now combined into one.

It is now up to the microbes to do their work and all humans can do is to wait!