A large amount of indigo is concentrated in the sukumo. 'Aidate' is the process of turning it into a liquid form through fermentation. A number of fermentation vats are buried into the half-raised floor of the Kosoen studio. At one place on the floor are two holes where in old days straw and wood scrapes were burned to maintain the temperature of the liquid in the vats. Nowadays electric wires keep the temperature much more stable.


Sukumo is put into a vat.

(2) [Moto-ishi]

Ash lye was added and then lime (moto-ishi) on top of it. Before using lye Mr. Murata sticks his finger into the cistern full of lye, to examine such things as its alkalinity.


The fourth ingredient is sake. Then mixture is stirred carefully with a bamboo pole ('Kai') so that all the ingredients blend well. The temperature of the solution should be around 30 Centigrade (86 Fahrenheit).


The solution is now ready for fermentation to begin; it needs to be stirred with a bamboo pole twice a day.


After a few days (the exact time differs according to the climate and the condition of the sukumo) a thin film can be seen on the solution (picture on the left), and a smell of ammonia comes from the vat. These are signs that fermentation is proceeding.

From this stage the temperature should always be kept around 25 Centigrade (77 Fahrenheit).

(6) [Kai-ire]

Kai is the bamboo pole and Kai-ire is the work of stirring the solution to ensure that the sediment at the bottom of the vat will be mixed and all the ingredients blended properly. This must continue for as long as the liquid is used.

to Aidate Part 2