This is the RICE KOJI !! Report of all hand process Rice Koji shop in Niigata

Can you see ??
This is one piece of Rice Koji.
Well, actually, one piece of rice which koji fungi propagates well.

Rice Koji. In another word, malted rice.
This is the very important ingredients of Japanese fermented seasonings,
such as Miso, Mirin, Sake, Vinegar, Shio-Koji, Shoyu-Koji, Ama-koji.
What kind of quality of Koji you use…that is very important.

Here is a small shop in Niigata

There is a five starts “Rice master” in this shop,
who has a passion for making good Rice Koji.

At his shop, they are making Rice koji in traditional way. All by hands.
Why handmade rice koji become good quality? Why it’s good?
Because…they can feel more information about Rice Koji’s condition than machine.
Temperature, moisture, then colour, smell, ..all conditions, which cannot really express in numerical form.
Hands are such a sensitive organ. You can see, you can smell, your hands can feel.
Then look for and make the best condition for Rice Koji.

Since his shop is in Niigata where is rice-producing region, especially Koshihikari rice,
he wants to use Koshihikari rice when he make Rice koji.

Niigata’s Koshihikari is probably the most expensive rice in Japan.
It was sweetness and nice stickiness.

Rice fields in Niitaga.


In autumn, it become like this, become gold all around.
It’s such a beautiful view.

This is how to make Rice Koji at his place.
It is very hard work, requires your five senses, but very interesting world.
I was so drawn into this world.

At first, soak the Niigata’s Koshihikari rice in the water overnight.
Then, steam rice for about 1 hour.

Then take some steamed rice out from this big steamer.
Literary, digging!!





As soon he place the steamed rice on the working table,
they start to trying to make rice into pieces.
I hope you get my meaning,
normally (especially Kohsihikari rice), when rice is cooked,
cooked rice is clustered, right?
They have to make rice unclustered so that Koji fungus can reach each rice pieces.
In this shop, their work is all by hands as mentioned before.
Some shops use chemical at this stage, but they are strictly working by hands.
Just to make good Rice Koji.

This work has to be done as quickly as possible, otherwise rice stick together soon.
They continue this work until the rice cool down to 31℃.
(According to them, they know what is 31℃ like by touching, they don’t need to use thermometer to check temperature. Amazing!)



Then sprinkle Koji fungus on these rice.
Very carefully.

Then mix them again!
It was really beautiful team work!!


Bring this lot to another room.
At this moment, rice is still just rice but, covered with Koji fungus.

This is the Koji room!! In Japanese, Koji muro (糀室).
Spending time (45H) in this room, Koji fungus will increase into/all over rice.


Rice (with Koji fungus) will be place in this box called Hegi.

So many of them!!

This is called Komo, which is made of rice straw.
This is like a blanket for Rice Koji.
This Komo is really good to adjust and control temperature and humidity,
which is very important elements making good quality Rice Koji.

Because they make these Komo by their hands,
they keep rice straw like this.
(Of course this rice straw is Koshihikari rice one!)

During sleeping in Koji-muro (for 45 hours),
they always look after Rice koji.
They have to check colour, smell/scent, feeling when they touch.
Use all of senses.
This is the difficult part, because every time, Koji grow different way.
This is the interesting part of dealing with “alive” thing.

So after 45 hours, Rice and Koji become lightly sweet Rice Koji! Finally!!


Depend on the purpose, different type of Koji fungus will be used to make Rice Koji.
See the difference.
Left = Whitish Rice Koji, Right = Yellowish Rice Koji.

In this shop, Whitish Rice Koji will be used for Amazake, Shio-koji.
Yellowish Koji will be making Miso.

Yes, they make nice Miso as well, and sell.


There was a wooden barrel, too!

At the shop, you can buy Niigata’s soybeans, good for making Miso!

They makes Shio-Koji (salted koji), too.
Of course, used the high quality Rice koji, which I have just reported.
If you are interested in Shio-Koji and want to purchase,
it is available now.
Please contact me.

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