It is fitting to divide making koji into two parts, as the entire process takes about two days.
The first thing in the morning, 7.30am to be exact, we went to the muro to check on the sleeping koji mountain. Although the koji was not visible yet, the rice was giving off a distinct ‘koji-smell’ and the temperature had climbed up to about 36C. It was now time to break down the mound of koji, which had become somewhat hard due to the loss of water, into very small clumps and move it into cedar trays (koji-hako). This work must be done to quickly to avoid the temperature dropping too much, which results in unhappy and slow-growing koji. After moving the koji into the trays, they were again covered with blankets to retain the heat and moisture. As it is very important to monitor the temperature in case it needs to be adjusted, we inserted two remote thermometers into a couple of trays which send a single to the unit on the first floor of the kura. A very handy tool indeed, as it saves continually climbing the stairs to the muro to check the koji temp.
After another day of growth, this koji-rice will be ready, and we will use it to feed the 400 L yeast starter culture. For those interested, here is a link to the blog of the sake brewery’s head brewer, and a picture of me in action: http://sawanohana.exblog.jp/.