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What is Fermented Brown Rice?

Koso Genmai (Fermented Brown Rice) is brown rice that cooked together with Azuki beans and salt, and fermented by keeping it in warm temperature for about two or three days.

Koso Genmai (Fermented Brown Rice) also called Nekase Genmai.

By fermenting the brown rice, you can:

⇒ Increase GABA (gamma-aminobutyric acid) and other nutrients that contained in the brown rice,
⇒ Enjoy the puffy texture,
⇒ Increase the umami flavour.


With its fluffy texture, even people who are not really good with brown rice could enjoy eating the fermented brown rice as well.

In this article, we would like to tell you how to easily make fermented brown rice at home.
Please try to cook it someday.

Click here to see our Recommended Product for Fermented Brown Rice


The Health Effect of Fermented Brown Rice

Since fermented brown rice usually use highlt nutritious brown rice, it contains many good ingredients such as protein, minerals, and vitamins.

It also contains abundant enzymes that are considered to be one of the most important elements for human activity.

Fermented brown rice is said to be the best dish for the efficient ingestion where enzyme components tend to be lost together with age.

Here we introduce the health effects from consuming fermented brown rice.


1. Relaxing Stress with GABA Ingredients

The GABA ingredients contained in fermented brown rice has the effect of relieving stress from daily life.

It can also help to improve concentration.

GABA ingredients have been drawing attention in recent years, such as its function to smoothen the neurotransmission process.


2. Help to Surpress The Blood Pressure.

Enzymes are important components to smoothen the digestion, metabolism, and blood circulation processes.

If you are lack of enzymes, nutrients can get stagnate in the blood, which can clog the blood flow.

Consuming fermented brown rice that contains enzyme can improve your blood flow,

it is expected to be the effective solution to prevent hypertension.


3. Good for your Diet

Fermented brown rice is also expected to lower the neutral fat cholesterol level.

The enzyme can breaks down the carbs and lipids that are likely to accumulate as subcutaneous fat in the body.

In other words, it can metabolized carbs and lipids without accumulating them in the body.

So it is expected to prevent obesity and improving your diet effect.

Consuming brown rice is also good because it contains lot of fiber.

Fiber allows to keep you fuller over a longer period of time, so maybe it could be a good reason to consume brown rice because it may help you consume lower calories overall/day.


4. Help to Solve Constipation

Like we said above, fermented brown rice contain lots of dietary fiber that is said to be effective to relieve constipation.

By activating the metabolism, it discharges waste precipitated in our body.

Not on that, fermented brown rice is also excellent in detoxification effect.

There are still so many nutrients and benefits from consuming brown rice.

According to studies, brown rice contains more nutrients compared with white rice.

So why don't we start consuming brown rice for healthier life style starting from today?

Click here to see our Recommended Product for Fermented Brown Rice


What do You Need to Prepare for Making Fermented Brown Rice

To make 4 portion of Fermented Brown Rice, you need to prepare:

Brown Rice: 600g
(Let's use organic product
if possible)
Azuki Beans: 50g Salt: 3g

Water:Appropriate Amount
(Please match it with the
capacity of your rice cooker)
Rice Cooker (We use
germinated brown rice cooker)

How to Make Fermented Brown Rice

There are four steps to make Koso Genmai:

Step 1: Wash brown rice and red beans
Step 2: Add salt and water and mix
Step 3: Immersion and rice cooking
Step 4: Warming and Fermentation

1. Wash brown rice and red beans


First, put the brown rice and azuki beans in the bowl, wash it slowly.

Clean the dirt and dust from the brown rice and azuki beans.


As brown rice absorbs water just like white rice, let's drain the water first.

Wash and drain the water, wash it again and drain the water, repeat for 3 or 4 times.

2. Add salt and water and mix it together


Add brown rice and red bean, water, salt and mix it together.


Please adjust the amount of water according to the capacity of the rice cooker.

3. Submersion and rice cooking


If you use a regular rice cooker, leave the brown rice in water for about 1 hour before cooking.


After that, we will cook the rice. If the rice cooker has brown rice cooking mode, please use its function.


If the rice cooker has germinated brown rice function, the process from germination to cooking rice can be done only by button operation.

4. Thermal Insulation and Fermentation


When the brown rice cooked, heat it with rice cooker for two until four days.


While keeping it warm inside the rice cooker, stir the brown rice once a day.

While keeping it warm inside the rice cooker, stir the brown rice once a day.
When stirring, use a rice paddle to stir it thoroughly once a day to prevent the surface from drying out.

If you concerned, you can prevent the rice from drying by using a wrap or wet cloth on the surface.
It will be ready to serve after two until four days of cooking.

Warming · Fermentation Day 1


The rice became slightly darker than normal brown rice.

Warming · Fermentation Day 2


The brown rice turned slightly purple.
The brown rice tastes richer compared to the first day.

Warming · Fermentation Day 3


As the fermentation progressing, the brown rice colour become darker.
The texture will get puffier.

Warming · Fermentation Day 4


Koso Genmai is ready to be consumed.
The umami flavour and its puffy texture are appealing.

Koso Genmai can be consumed for about 7 days after it's done cooked.

With four steps above, the making of delicious and puffy Koso Genmai is completed.

By fermenting it, the bad part of brown rice will vanish and be replaced with its delicious taste.
By fermenting and keep the rice brown warm, it will produce melanoidin (brown coloured component in food). Due to the antibacterial action from the melanoidin, brown rice becomes Koso Genmai without corrosion or decay.


Furthermore, by fermenting the rice brown, it is said that the nutrient called GABA (gamma-aminobutyric acid) will increase even higher than the normal brown rice.

It should be noted that in this video, we use rice cooker with germinated brown rice function.

It is recommended to use the rice cooker with such function because you can eat Koso Genmai simply by button operation.
Please try to cook and enjoy the delicious Koso Genmai at home.

Recommended Product for Fermented Brown Rice

Handmade Koso Genmai
(Fermented Brown Rice) Set
(3 Combination)
This is the original Koso Genmai set from Kawashima The Japan Store. We are using the organic, non-pesticide and non-chemical addictives ingredients for making Koso Genmai. It is a convenient pack of the main ingredients for making Koso Genmai (fermented brown rice): brown rice, red beans, and salt.

Not only good for your health, but it also have a delicious taste but has a fluffy texture. Please try to easily make handmade Koso Genmai.
Country of Origin: Japan
Product Page
Ogata Health Farm's Hinohikari
Organic Brown Rice 2.5kg
This is Ogata Health Farm's self-confidence work based on the wish to help every family to become a happy family without any disease. For around 20 years, Hinohikari is rice of non-chemical cultivation without any pesticide, chemical fertilizers, herbicide, etc. A pure rice with small grains but contains high energy in every grain. The production volume is limited to a small quantity.This rice is very ideal for you who want to fix an atopy or rice allergy.
Country of Origin: Japan
Product Page
Akiba Farm's Red Beans 200g
(no pesticide, no fertilizer, natural cultivation bean)
The adzuki (red bean) from Akiba Farm in Kitami City, Hokkaido Prefecture that is raised in natural cultivation that doesn't use pesticide or fertilizers.

Because it is very difficult to not use any fertilizer, it is said that there are less than 100 people nationwide that actually done it. This beans are also naturally dried in the sunlight, so it increases its adzuki's original flavour, sweetness and umami.
Country of Origin: Japan
Product Page