How sake is made?
Chigonoiwa Shuzo (Sake Brewery) in Toki-city, Gifu prefecture

Gifu prefecture is located in Chūbu region of central Japan. Taking advantage of its rice and clear water, Gifu prefecture has about 50 sake breweries, and is the 7th largest number of breweries among Japanese prefectures.


In this article, I’m going to talk about one of sake breweries in Toki-city, Gifu prefecture, Chigonoiwa Shuzo, based on an interview to Mr. Nakajima, the 4th generation of sake brewing master since 42 Meiji (1909). Sake in Chigonoiwa Shuzo has a relatively gentler fragrance and refreshing aftertaste. In order to keep these features, they have been very particular about the ingredients and brewing method.

Strong preference for the ingredients:

They draw up water from 45m underground, at their own well inside the brewery. Use of this extremely soft water (7ppm) will result in the tender and gentle taste. They also use rice from Sakaori Rice Terraces in Ena-city, Gifu. Sakaori Tanada (Rice Terraces) is elected to be one of the 100 best rice terraces in Japan. Rice Terraces are series of rice fields on a sloped plane of a mountain, and are in a good environment for making rice that are rich in sweetness and nutrients, because of its large difference in temperature between morning and night.


Sakaori Tanada (Rice Terraces)


Preferred Method:

Our goal is to make sake with a gentle fragrance, and sharp and refreshing aftertaste, because it is sake drunk during the meal. The most important key for making preferred taste of sake is koji. In Chigonoiwa Shuzo, koji is all handmade as it will be the pivot of the taste. During 3-day-long koji processing, koji mold is sprinkled onto steamed rice, and it requires a very strict temperature control to be able to make the refreshing aftertaste.

How sake is made?

The main ingredients of Sake are rice and water. The first step of brewing sake is to convert starch inside the rice into sugar, using the effect of koji. As the sugar turn into alcohol, it becomes Sake. A taste of Sake varies as you use combination of different kind of water and rice, and also different method of processing koji. These differences make the variety of taste among Sake producers across the country.

How sake is made


Process of brewing Sake

Step 1 Steaming rice: After washing and soaking, steam the rice.
Step 2 Making koji: Some part of steamed rice will be the base material of koji. This is the most important process in Sake brewing in order to make preferred taste. Tip the steamed rice onto a work surface and sprinkle koji mold onto it. Then, wait until the mold is propagated.
Step 3 Making yeast starter: Mix the teamed rice (step 1), koji, water, and yeast, and proceed the fermentation. This is a porridge-like starter that weeded out an unnecessary sterilization.
Step 4 Making moromi: Add some steamed rice, koji, and water into the yeast starter that you made in the Step 3.
Step 5 Fermentation:Inside the moromi, saccharification and fermentation will happen at the same time. Koji will convert starch inside the rice into glucose, and the yeast will convert sugar into alcohol and natural gas.


Step 1: Steamed rice

Polish the rice. Use different polishing rate (70%, 60%, 35%, etc.) as you use different production brand. By removing unnecessary protein and lipid, you can make tasty sake with less unpleasant taste.

Wash the rice, and then soak it in water. We soak moreSake_Step1 than 500kg of rice at once by using this machine (on the picture).

<The center picture> There are rice and water inside the upper part of the machine

Soak in water for 12 – 12.5 min if the rice is 60% polished, 9 – 9.5min if the rice is 35% polished.

It will require you a long-term experience to measure how long the rice should be soaked, by looking at the condition of rice, temperature of water and room, humidity, and the length of time since the rice is polished.

By steaming this washed rice for 55 min in the early morning of the next day, you have finally completed making steamed rice.

<below picture>Rice after soaking 





Step 2: Making koji

Now, let’s move on to the process of producing koji by fermenting koji mold onto the steamed rice. In order to make koji, mix a small amount of koji mold with steamed rice inside the kojimuro (a room for producing koji), and then keep it warm by wrapping it with a cloth, and proceed the fermentation very slowly and gently.

Because koji mold for sake has to be mixed and piled up over and over again, it can be very stressful during koji making.



As the temperature of koji reaches 38 °C (100.4°F), corrugate the surface as you see it in the picture. The reason of doing corrugation is to dry it faster by enlarging the surface. When the temperature of koji is between 35°C and 37°C (95°F and 98.6°F), enzyme that makes unpleasant taste will be produced a lot. Pass through this temperature zone quickly. Also, to make koji tightened, raise the temperature to 48°C (113°F), while drying it. If you bite the koji by your back tooth, it will release chestnut-like sweet fragrance and taste in your mouth. Tightened koji will result in refreshing and sharp feature of sake.

Remove the completed koji from kojimuro, and then cool it. By corrugating the surface, you can cool it evenly and quicker.


Step 3 – 4: preparation of yeast starter and moromi

Yeast starter is made of fermented mix of steamed rice, koji, and yeast. And adding koji, water, steamed rice into the yeast starter, makes moromi.


Left: Moromi tank, Right: Inside the tank

add koji, water and steamed rice into the yeast starter and ferment it. It will take you 4 days to do this process. If you prepare too much at once, the amount of yeast mash will decrease and it will result in fermentation of unwanted bacteria. You need to prepare in several stages.

Step 5: Fermentation

A week after the beginning of preparation, moromi will become foamy as a result of proceeding fermentation. Before the foam runs off the tank, remove it by using the wire that is attached to the top of machine, as you can see it in the picture.

As the fermentation proceeds further, the foam will start to go down, and eventually it will disappear.



Twice a day, (every morning and every night) you need to stir your moromi with an oar. In this process, you don’t just stir it, but uniformly mix the entire moromi. If you stir too much, it will become unfavorable taste. But if you don’t stir enough, fermentation may not proceed properly. It requires a very delicate operation.


A condition of fermentation has to be measured and analyzed everyday. It requires a delicate balancing of saccharification and fermentation to make sake (parallel multiple fermentation). Koji mold and yeast mash are organisms that are invisible to the naked eye (microorganisms). It needs to be scientifically scrutinized to keep good condition of moromi. The 6 main analyses are: SMV (Sake Meter Value), alcohol content, acidity, amino acid degree, sugar content, and pH. Plus, microscopic examination of microorganisms such as yeast mash and lactic acid bacteria has to be done.

Saccharification makes starch converted into sugar, and fermentation makes the sugar converted into alcohol. Alcohol content is calculated by analyzing the specific gravity of the alcohol that is created by the fermentation.

Thus, keeping a good condition requires not only intuition of a sake brewing master, but also the scientific examinations and analysis of data.

Putting a lot of effort and time, you have finally finished your sake brewing.



About Chigonoiwa Shuzo (千古乃岩酒造)

Address: 2177-1, Dachi-cho, Toki-shi, Gifu-prefecture
Web site:

Contact:  Contact from here at their web site.

Chigo No Iwa Shuzo was established in 1902 in Toki City, Gifu Prefecture.  Daizo is a Master Sake Brewer (Toji/杜氏) whchigonoiwa-nakajima-sano manages his family business.

Sake “Chigonoiwa” is a local brand of sake. The founder Shigezo Nakajima named it “Chigonoiwa”, after an exquisite stone found locally, with the hope that it would grow and be success in 1909.
It is made by the skill of the master teaching of the “Echigo master brewer”. Marvelous balance between seasons and climate produces tasty sake.