In the land of Fungi, the Oryzae of the Aspergillus village and the Cerevisiae of the Saccharomyces village have large families with lots of cousins.
Some of them found life employment at Marutaka, in Kamisuwa (Nagano Prefecture). Marutaka has been crafting miso paste for a hundred years, in a Kura which is now classified as important cultural property. Mr. Kobayashi led us through the fabrication process and the plant. Nagano rice is steamed and inoculated with an aspergillus to produce Koji. Enzymes released by aspergillus slowly transform the starch into fermentable sugars, and proteins in amino acids. Such Koji is mixed with boiled then mashed soybeans (from Nagano!), as well as salt. Saccharomyces (yeast) is then introduced. The proportion of rice to soybean, the quantity of salt, the temperature at which the mixture is left fermenting, as well at the length of time of such fermentation and/or the subsequent maturing process determine the aromatic profile, the concentration of flavors including umami, and the color (from light ochre to dark brown). While their domestic market is declining, some of Marutaka’s beautiful miso pastes found their way to the United States or Paris for example, and the company has been developing a range of miso based products. Amongst differences to their peers in Nagano, the leading Prefecture for miso, Marutaka harnessed the heat of local onsen waters to keep the fermentation room above 20 degrees Celsius, enabling year long production. In addition they leave naturally produced alcohol into the miso.
Marutaka is a branch of the Miyasaka Jozo company, which has been brewing sake since 1662, using the Masumi brand. We paid a visit to the nearby cousin Kura afterwards, which itself employs Oryzae and Cerevisiae cousins for sake, in a not too dissimilar fermentation process.
Perhaps now you may grasp better why sake and miso are often associated in Japanese cuisine to marinate fish or meat, and why they enhance each other when paired in the mouth during a meal. Long life to cousin reunions.