Koji Starter For Soybean Koji (For Making Kinzanji Miso) 100g (For 200kg Portion) - Special Product From "Hishiroku" Shop Kyoto, Japan

Koji Starter For Soybean Koji (For Making Kinzanji Miso) 100g (For 200kg Portion) - Special Product From "Hishiroku" Shop Kyoto, Japan


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What is Koji Starter for Soybean Koji?

Established 300 years ago, this is the koji starter (koji seed) made by the long-established store "Hishiroku".

This koji starter is a koji starter for soybean koji and is very suitable for making kinzanji miso. Kinzanji miso is a mixture of kinzanji koji (mixed rice koji, barley koji, and soybean koji) and chopped vegetables, such as eggplants, cucumbers, shiso, carrots, ginger roots, etc.

Use this high-quality koji starter for making soybean koji, and you can make your own kinzanji koji by mixing it with koji rice and barley koji.

With your delicious kinzanji koji, you can make delicious kinzanji miso!

Koji Starter for Soybean Koji Seed

This product contains 100g of koji starter (Aspergillus) that can be stored for a long time in a convenient sachet package, so you can open it just as much as you need.

100g of this koji starter can be used for 200kg of soybeans in koji-making (the weight of soybeans before adding water is 200 kg).

What is Koji Starter/Koji Seed?

Koji starter or koji seed is the Aspergillus spore that becomes the source of koji.

In the brewing industry, we call the koji starter "sprouts". We can make koji to produce fermented foods such as miso and amazake (sweet sake) with these sprouts.

The appearance of the koji starters bud popped out, and its whitish hyphae grow the bean sprouts and budding trees figure, so it's called like that.


Various Kinds of Koji According to the Purpose

Chouhaku-kin Koji Starter

Chouhaku-kin Koji Starter
  • For making Amazake (Sweet Sake): Very suitable
  • For making Shio Koji (Salt Koji): Very suitable
  • For making White Miso: Very suitable
  • For making Rice and barley/wheat miso: Suitable
  • For making Bean miso: Suitable
  • For making Shouyu (Japanese soy sauce): Suitable
Chouhaku-kin Koji Starter Color

The finished result is white koji. Basic koji starter that suitable for any kojis.

Kairyou Chouhaku-kin Koji Starter

Kairyou Chouhaku-kin Koji Starter
  • For making Amazake (Sweet Sake): Very suitable
  • For making Shio Koji (Salt Koji): Very suitable
  • For making White Miso: Very suitable
  • For making Rice and barley/wheat miso: Suitable
  • For making Bean miso: Suitable
  • For making Shouyu (Japanese soy sauce): Usable, but not recommended
Kairyou Chouhaku-kin Koji Starter Color

Ideal for amazake (sweet sake). The finished result is the most white-colored that other koji starter. Recommended for white miso.

Koji Starter for Miso

Koji Starter for Miso
  • For making Amazake (Sweet Sake): Usable, but not recommended
  • For making Shio Koji (Salt Koji): Usable, but not recommended
  • For making White Miso: Usable, but not recommended
  • For making Rice and barley/wheat miso: Very suitable
  • For making Bean miso: Suitable
  • For making Shouyu (Japanese soy sauce): Suitable
Koji Starter for Miso Color

Ideal for rice and barley/wheat miso. The finised result will have a balanced taste.

Kinzanji Koji Starter

Kinzanji Koji Starter
  • For making Amazake (Sweet Sake): Usable, but not recommended
  • For making Shio Koji (Salt Koji): Usable, but not recommended
  • For making White Miso: Suitable
  • For making Rice and barley/wheat miso: Suitable
  • For making Bean miso: Very suitable
  • For making Shouyu (Japanese soy sauce): Suitable
Kinzanji Koji Starter Color

Ideal for bean koji. Increase the flavor of bean miso (mame miso).

Koji Starter for Shouyu

Koji Starter for Shouyu
  • For making Amazake (Sweet Sake): Usable, but not recommended
  • For making Shio Koji (Salt Koji): Usable, but not recommended
  • For making White Miso: Usable, but not recommended
  • For making Rice and barley/wheat miso: Usable, but not recommended
  • For making Bean miso: Usable, but not recommended
  • For making Shouyu (Japanese soy sauce): Very suitable
Koji Starter for Shouyu Color

Ideal for shouyu (Japanese soy sauce). It will have delicious result.

More Fermented Foods Recipe from Kawashima The Japanstore

What is Koji?

Give water to raw grains (rice, barley, beans, etc.), sprinkle seeds on steamed grains, and culture the seeds under temperature conditions suitable for the growth of Aspergillus oryzae.That is how this koji starter is made.

Koji has so many enzymes that it is said to be a treasure house of enzymes and could decompose grains with its power. Also, koji itself is a nutritious food filled with sugar, amino acids, vitamins, minerals, etc. All these nutritions are made by the koji starter (Aspergillus oryzae).
With koji, you can make traditional fermented foods such as sake, authentic shochu, mirin, miso, soy sauce, vinegar, amazake (sweet sake), etc.

miso amazake shoyu

Health Benefits of Koji

When the intestinal environment (intestinal flora) gets better, your skin condition will be better, and immunity will be improved. It is a fermented food that arranges this intestinal environment. And, fermented foods are always made by microorganisms that induce fermentation.

The familiar ones are Aspergillus oryzae, Bacillus natto, Lactobacillus, and other bacteria/fungus. The one that creates miso, shouyu (Japanese soy sauce), and sake is koji starter (Aspergillus oryzae). This koji starter (Aspergillus oryzae) matches well with Japan's climate, and it was found in the Muromachi Period (1336–1573).

Major Nutrients of Koji
Vitamin B1

・Helps produce energy
・Fatigue recovery
・Suppress irritation/stress feeling
・Amnesia prevention
・Helps breaking down carbohydrates

Vitamin B2

・Helps the metabolism of skin
・Helps breaking down lipids
・Accelerate growth speed
・Sebum control
・Prevent oral ulcer/stomatitis

Vitamin B6

・Reduce premenstrual syndrome (PMS)
・Improve immunity
・Prevent arteriosclerosis
・Helps breaking down proteins and lipids
・Prevent oral ulcer/stomatitis
・Suppress the excitation of nerve cells

Vitamin H (Biotin)

・Suppressing the cause of atopic dermatitis
・Prevent diabetes
・Alleviate epilation and gray hairs

Pantothenic Acid

・Stress resistant
・Helps breaking down lipids
・Detoxification from chemical compound
・Increase good cholesterol
・Maintaining the health of skin
・Increase immunity

Essential Amino Acids

Among the 20 types of amino acids making up proteins, nine kinds of them can not be synthesized in the body. If there are any lacks of them, muscle, blood, bone cannot be made. These nutrients can be consumed in supplements, but when ingested from koji based food, the absorption rate in body is over 90%.

How to Make Barley Koji

Barley koji is used as the raw material for making Japanese fermentation food such as barley miso (麦味噌), kinzanji miso, and shoyu. At the sake brewery, barley koji also used to make barley shochu (麦焼酎).

The barley miso made with barley koji has a lighter taste than the rice miso made with rice koji. This type of koji has a unique fragrant aroma from barley that becomes its charm point.

Barley Miso (left) and Kinzanji Miso (right)

Barley Miso (left) and Kinzanji Miso (right)

Related article
How to Make Barley Koji Article
How to Make Barley Koji
Barley koji is one type of koji, made by cooked barley that has been inoculated with koji mold (koji kin). With barley koji, you can make various foods, such as barley miso. In this article, we will explain how to make barley koji (using koji starter...


Work Process of Making Soybean Koji

Wash the soybeans → Soak the soybeans in water → Sprinkle the koji starter on soybeans → Keep it warm → After 18-22 hours → Stir it ① → After 5-22 hours → Stir it ② → After 7-8 hours → Complete!

Tools and Ingredients of Making Soybean Koji

Required Tools and Ingredients
Soybeans (proper amount as you like) Koji starter for beans Steaming cloth (2 sheets) Koji fermenter (fermentation device; you can also use Yogurtia or cooler box)


More Convenient If You Have
Thermometer Rice paddle Strainer, tea strainer Koji box (box for koji)

In order to avoid the breeding of germs, wash the tools clean and properly.
You can disinfect the tools by boiling them.

The Steps of Making Soybean Koji

1. Wash the soybeans, then soak it in water.
2. Boil the soybeans.
3. Sprinkle the koji seed (koji starter) on boiled soybeans (seeding).
4. Keep the soybeans warm.
5. Stir the in-fermenting-process soybeans (First maintenance of koji) (After 18-22 hours)
6. Second maintenance of koji (After 22-42 hours)
7. Complete!

With these 7 steps, you can make high quality soybean koji.
Let's start making koji!

Step 1. Wash the Soybeans, then Soak Them in Water

Wash the soybeans properly.
After that, discard the dirty water. Then add clean water in the bowl until the soybeans are completely immersed in water.
Wrap it with plastic wrap, and soak the soybeans for about 24 hours.
When the temperature is high such as in summer, put it in the refrigerator.

Step 2. Boil the Soybeans

Pour the soybeans along with the water used to soak them into a boiling pan, then boil the soybeans.
First, boil the soybeans with high heat until the hot steam rises, then turn to low heat and steam them for 2-3 hours.
If the soybeans became soft enough that when you pinch it with your thumb and index finger it can be easily crushed, discard the hot water. And so the surface of the soybeans can be dried, move the pot and let the hot steam flow away.

Step 3. Sprinkle the Koji Seed (Koji Starter) on Boiled Soybeans (Seeding)

When the soybeans are bolied up, put and spread it on a clean tray or a clean dish cloth.
Please be careful not to burn yourself.
Use a fan to cool the temperature of soybeans.
When the temperature of the soybean have cooled down to 36 degrees, sprinkle the prepared koji tarter seed and mix it thoroughly (this step is called "seeding").
The amount of koji starter is usually about 2g of koji starter on 1kg of soybeans.
For people who try to make barley koji for the first time, it's easier to succeed the breeding of the koji starter if you use 2 times of that amount.
During this step, please prepare the koji fermenter/warming device and warm it until 30℃.

Step 4. Keep the Soybeans Warm

After the seeding step, move the soybeans to a koji box and spread them flat and thin (about 2-3 dm of thinkness).
So that the soybeans isn't dried off, cover the flattened soybeans' surface with a firmly squeezed clean cloth (disinfect the cloth first with boiling water).
Put it in 28-30℃ pre-warmed fermenter device.
If you keep a humidity by putting a tray of water in the fermenter, there is no need to cover with cloth.

Since soybean koji is more vulnerable to various bacteria than rice koji and barley koji, keep the soybean temperature below 30℃.

For making this koji, the optimal temperature for breeding the koji starter (Aspergillus oryzae) is around 28-30 degrees. Please keep the rice warm at this temperature.
Please be careful for not to drop the temperature.

Step 5. Stir the In-fermenting-process Soybeans (First Maintenance of Koji) (After 18-22 hours)

By this time, the temperature of soybeans will rise.
Stir (mix) the soybean, lower the temperature and make the thickness of soybean same on all the surfaces.
Stir the soybeans quickly so that the temperature of soybeans doesn't extremely go down.
Also, when stirring soybeans, wash hands and utensils thoroughly.

Step 6. Second Maintenance of Koji (After 22-42 hours)

When 5-6 hours passed after the first maintenance of koji, the koji seed will breed further and the soybean temperature will rise again.
Please take out the koji box from the fermenter device and lower the soybean temperature to 28-30℃.
When the temperature of soybeans rises too much, please lower the temperature by stirring the soybeans.
If the temperature rises up too much, contamination by natto bacteria etc. will occur, causing the failure of the koji's completion, so please be careful.
To not raise the temperature of the soybean too much is the important point in the making of soybean koji.

Step 7. The Completion of Soybean Koji

If the surface of the soybeans is covered with green spores and the soybeans became loose, then the soybean koji is ready. Please check the breeding/growth condition of koji.
If there is no problem in the breeding condition of koji starter on soybean koji, the it's completed.
You can use this finished soybean koji to make miso, etc. in your home!

How to Store Soybean Koji

After the soybeans koji is completed, it's recommended to use the koji as soon as possible. Even if it is kept in the place where the temperature is low and the wind circulation are good, if the mass of the koji rice is thick, the fermentation will not stop and the quality of the koji may deteriorate.

If you plan to save the koji rice for 1-2 days after it's finished, please untangle the clumps in koji rice by massaging it, then spread it as thin as possible and keep it in a cool place.


Store in the refrigerator: about 2-3 weeks

When storing in a refrigerator, put it in hygroscopic (material that tends to absorb moisture from the air) paper bag.
In the refrigerator, it's possible to save the koji rice for about 2-3 weeks.


Store in the freezer: about 1-3 months

If you plan to use it later for a long time, put it in a zip lock (a plastic bag with zipper/fasterner), etc. and keep it in the freezer.
It's possible to save the koji rice for about 1-3 months in freezer.

What A Good Soybean Koji Is


From a good soybean koji, a good aroma like roasted beans will come slightly. If there is an unpleasant smell like a sour smell or a nasty smell, it's most likely that germs have entered and rotted.

Also, spores are grown strongly on good soybean koji. Its texture will be crumbly and not sticky.

If you want to check it more detail, cut the bean grain with a knife and look at the cross section. A good soybean koji has a thin white layer between soybeans and spores.

The Amount of The Koji Rice That Can be Made and the Amount of Rice and Koji Starter Used

Portion of rice

Portion of koji starter

Amount of finished koji (estimated)

The Amount of The Koji Rice That Can be Made and the Amount of Rice and Koji Starter Used

Note: 合 is a Japanese unit of measurement, usually used to measure rice, sake, etc. (1合 equal to approx. 150 grams, 0,18 liters, or 0,33 metres square)

This table references the amount of koji rice and koji starter seed.
It's easier to make koji rice for the koji starter if you use koji starter in a larger amount. There will be no problem even if you use a lot of koji starters.

The Amount of Miso That Can Be Made and the Amount of Ingredients Used

The Amount of The Koji Rice That Can be Made and the Amount of Rice and Koji Starter Used

This is the portion for miso with salt concentration 12.5% (sweet flavor).

For the details related to koji rice, please go to these pages:

Related article
How to Make Koji Rice Thumbnails
How to Make Koji Rice
This tutorial was provided by the koji manufacturer themselves, and summarized by Kawashima The Japanstore. Feel free to use this as a reference to make rice koji. We hope that you can make good rice koji. Now, let’s get to it!
Related article
Recipes that Uses Koji Rice Thumbnails
Recipes hat Uses Koji Rice
Shio Koji, also known as Salt Koji, is made up of rice koji, salt, and rice. Shio koji has been widely used in Japan with ancient origins as a seasoning or ingredient, particularly for fermented foods.
Related article
How to Make Amazake Thumbnails
How to Make Amazake
Amazake (Sweet Sake) is a Japanese energy rice drink made from koji (Aspergillus Oryzae) and rice. It is known for its health benefits since Japan’s Kofun Period.

The Benefits of Handmade Koji Rice

You know exactly what ingredients are being used.

Formerly, miso, shouyu, amazake, etc., were homemade with koji in the Japanese family. However, eating habits change with time, and miso, shouyu, amazake changed from "things to make" to "things to buy." Under such circumstances, many people are uneasy because they don't know what type of rice is used in foods such as miso and shio koji (salt koji) available at supermarkets, etc. If it's handmade, you can make it with pesticide-free rice prepared by yourself, so it's safe.

Handmade is fun!

When Kawashimaya's staff tried to make handmade koji rice, they were impressed that their hands became so smooth. It's a famous story that because they engage in sake-making, the hands of a chief brewer at a sake (Japanese liquor) brewery are beautiful. In koji rice's nutrients, there are a lot of components that make the skin beautiful. Then, if you make koji rice by yourself, you will take care of it like your own child. Thus, the miso and amazake you made will become more delicious.

It's more economical.

When making miso, you will need koji in kilograms. If you buy it, it will be really pricey. For that, if you make your own koji using a koji starter (Aspergillus oryzae), it will be much more economical because you can even make koji rice from 15kg of rice.

Handmade Homemade Koji

The Steamed Rice
The Steamed Rice, is What Determines the Quality of Koji Rice

If the rice used in koji rice making is cooked with a rice cooker or the like, the amount of water (60% or more) becomes too much, and it won't be finished as good koji rice.
In order to make the rice with moderate water content (about 38%), it's necessary to "steam" the rice with proper steam.
The koji-making professionals make steamed rice with a bamboo steamer (seiro).
Furthermore, by using a steaming cloth made of tetoron, the time loss (temperature drop) caused by the rice sticking on the cloth can be eliminated so that you can do the seeding step (sprinkling the koji starter on steamed rice) smoothly.

Koji-making Professionals' Favorite Tools! Koji-making's Best Friends

Tetoron Cloth
Tetoron Cloth

Strong against high temperature, excellent in steaming.
Rice won't stick to the cloth, a convenient steaming cloth.
It's also useful for moisture control during the warming of koji.

Seiro (Bamboo Steamer)
Seiro (Bamboo Steamer)

Steamed rice is the key to making koji.
Using bamboo steamer/seiro, steam the rice with high heat for about 40 minutes.
It's also a helpful tool for daily dishes.

Steamed Rice
Tips for Making Steamed Rice from the Professionals

A bamboo steamer is recommended to steam the rice!
Cover the steamer basket when steam/vapor comes out from the surface of the rice and the surfaces become transparent.
Steam it for about 40 minutes (recommended) after putting on the lid.
When steaming in the bamboo steamer with two or more rows, change the order of rows midway through the steaming process.

Message from Hishiroku Corp., the Maker of Koji Seed Starter - Special Product from Hishiroku Shop, Kyoto

Hishiroku Corp.

In the main region of "The Land of Royal Castle" of Kyoto, standing there for over 300 years is the reputable "Hishiroku" Shop. In its long history, we devotedly making steady progress of koji starter (koji seed).

We believe that small activities hidden in koji starter's Aspergillus will eventually produce big things and will become life force for tomorrow, so we are making research and efforts to deliver the pure, stable, and high quality products of koji starter.

We are looking forward to your further patronage in using Hishiroku's koji starter for making koji.


Q & A About Koji Starter

How long is the life of a koji starter (koji seed)? How long can I keep it?

・ If the package is unopened and stored in a vegetable compartment of a refrigerator, the standard storage period is about 6 months.
・ After the package is opened, please seal it with a ziplock, etc., and save it in a vegetable room of a refrigerator. With this, you can save the koji starter for about 6 months.

How can I store the finished koji rice?

・ If you want to store it for 1-2 days, please put it in a cold dark place with a temperature lower than 15ºC.
・ If you want to store the koji rice for 2-3 days, please put it in the refrigerator.
・ If you want to store it for more than 3 weeks, please put it in the freezer. In the freezer, the koji starter can be saved until 3 months.

Can I drink koji starter as it is?

Since it's not a drink, please do not drink it. If you look for a supplement product, we recommend you to try KAWASHIMAYA "Lactic Acid Bacteria Powder" - Probiotic Supplement Taken from Japanese Fermented Foods (100 g)

How much should I use the koji starter when making koji rice?

The amount of koji starter is about 1.3g-10g for 1kg of rice (rice for raw material) (about 0.2g-2g per 150g of rice).
If you are still not used to koji rice making (first-time try), it's better to use the koji starter more.
Because even if you use much of it, there will be no problem.

About the finised amount:
・ The steamed rice will be 1.8-2 times heavier than the original/raw weight if you steam the rice.
・ Then, after the koji rice is completed, the weight will be 0.9 times the weight after steaming. Thus, the finished rice koji will be 1.62 (1.8x0.9)~1.8 (2x0.9) times from the original/raw rice weight.
・ For example, if the raw rice is 1kg, the finished amount of koji rice is 1.62-1.8 kg.
(This is an estimated amount. The amount of finished koji rice depends on the soaking condition, steaming condition, and the condition of fermentation process).

The color of the finished rice koji is reddish-brown and smells strange. Can I use it?

There is a high possibility that other bacteria are mixed and increasing in the process of making it. Please don't use it.

After you have sterilized all the equipment, please try increasing the amount of koji starter when making koji rice next time (about 3-4 times more) so it's easier to ferment.

In addition, please be careful about temperature control during the fermentation process.

Customer's Voice

This is the first time I tried to make soybean koji for making soybean miso.

I was a little worried because I couldn't adjust the temperature well, but the result came out just like soybean koji.
I think I can try it more smoothly next time. So, I will repurchase.
(Ms. S, 30s)

I bought it this year because I wanted to make koji for making homemade soybean miso.

I was impressed that the beans could ferment well with the koji starter (aspergillus). I'm even more attached to making miso from scratch.
I'm looking forward to the finished miso.
(Ms. Y, 40s)

I always use the white-type of koji starter from the Hishiroku store to make koji.

I have made koji more than 30 times, but I have never failed.
This koji starter product is helpful because you can make various fermented foods using homemade koji.
(Mr. H, 30s)

It takes a while to make it, but I like it.

I like it's because it's much cheaper and produces a better quality of koji rice than the ones being sold in the market. (Ms. Ito, 30s)

Need More Info About The Koji Starter's Enzymatic Contents?

We have compiled more informations about our koji starters. Please click the button below for details.

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Product Details
Name Koji Starter (Koji Seed) for Soybean Koji - Best for Making Kinzanji Miso
Netto 100g
Expired Date About half a year
Storage Guide Please put it in cold dark place with temperature lower than 15ºC.
Koji Starter for Soybean Miso - Best for Making Kinzanji Miso
    Important Points
  • Be sure to clean up tools, clothes, hands, etc., correctly, and be careful with germs.
  • Please use it as soon as possible after you open it.
  • This product is for rice koji and barley koji. Please do not use it for other purposes.
  • We will deliver it in a thick envelope.
  • Why shop with KAWASHIMAYA?