11. Producing the secondary mash
Water and the steamed rice, the key ingredient in rice shochu, are added to the primary mash to facilitate the fermentation of the alcohol. This process is known as secondary preparation.
The mixture is then stirred with a paddle to dissolve the ingredients and encourage fermentation, and it takes around two weeks for the mixture to mature.
The preparation pots used to store the mixture are small and buried in the ground to prevent any effects of changes in temperature, making it easier to perform any fine-tuning, such as managing the temperature and churning the mixture.