Natto Chunggukjang Doenjang Miso Sufu Tempeh Yeot Idli ShuiDouChi Thua Nao Kinema Douchi Chou Tofu

Grain fermentation using various aspergillus…
Is it safe to maje these at home, knowing that some aspergillus may produces highly carcinogenic aflatoxins?

A document (in french), taken from this web site. Note that this "Institut Pasteur de Lille" is not a very serious scientific structure (it borders scientific misconduct in its relationships with the anti-cholesterol industry).

A japanese link about Natto

Another Natto link

A scientific paper about Thua Nao

Himalaian Kinema, etc...

Natto, ShuiDouChi, Thua Nao, Kinema,....

Doenjang making

Cheonggukjang making

Tempeh.info : everything about Tempeh!

from this link: How to make Natto

Making Natto is a typical process of fermentation.

1. Choose starting materials (or substrate 底物)-Soybean: use small size of soybean as it is easier for reactants (water, oxygens, bacteria etc.) penetrating into the center of soybean to have the reaction done.

2. Prepare the soybean: The beans are washed and soaked in water for 12 to 20 hours. This will increase the size of the beans to 130%. Next, the soybeans are steamed for 6 hours, but a pressure cooker can be used to reduce the time. The rationale behind is to break down the protein (big molecules) into smaller pieces which are easier for bacteria to take use of later on during fermentation. If you boil the beans, don't throw away the soup but keep it in the frig for later use.

3. Prepare the bacteria: we need a special strain of bacteria called Bacillus subtilis natto which actually comes from the rice straw easily found in the farm field in Asia. This type of bacteria has spore (孢子) which is very resistant to high temperature but grows fast at 40°C. You might be able to get such bacteria in a dry package from local Japanese shop (ask for nattō-kin in Japanese) Or if you want to make some funs (not recommended though), just collect some dry grass and boil them in the pan for 20 min to kill other microorganisms you don't need. And if you can't find this, never mind, as there are some naturally remaining 'natto germs' on the beans you can use to grow.

4. Fermentation 1: Mix the beans with the bacterium. From this point on, care has to be taken to keep the ingredients away from impurities and other bacteria. The mixture is fermented at 40°C for up to 24 hours. If such temperature is not available in your place, leave the fermentation a bit longer, e.g. 3-4 days at 20°C.

5. Fermentation 2: the natto is cooled. Add the soup you used to boil the beans into the fermented beans. Then aged in a refrigerator for up to one week to add stringiness. During the aging process at a temperature of about 0°C, the Bacilli develop spores, and enzymatic peptidases (subtilisin) break down the soybean protein into its constituent amino acids. You will find the beans become sticky, partly because of flagella (鞭毛) - the hair or feet at outside surface of bacteria used to move around. The beans become a bit stinky (like the spoiled beans) and sticky. 粘乎乎,有点馊臭味最好

6. Taste modification and enhancement: If you don't like the native smell of natto, then you can modify the taste a bit. In China, we add the following ingredients: a bit hard liquor, minced ginger, fresh minced chilly pepper, Sichuan pepper and salt. Further store them in frig for 3-4 days before you eat the natto.

Making CheongGukJang :

Cheong Guk Jang can be made in 2 to 3 days through fermentation of boiled soybeans, adding Bacillus subtilis, which is usually contained in the air or in the jip, dried rice plants, at 40 degrees Celsius without adding salt, compared with the much longer fermentation period required for doenjang, another, less pungent variety of Korean soybean paste. Like many forms of doenjang, cheonggukjang is paste-like in texture, but also includes some whole, uncrushed soybeans.
Cheonggukjang may also be made by fermenting boiled soybeans in a warm place, pounding a portion of them, and adding salt and red chili powder.

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