INSTRUCTIONS FOR NATTO

Homemade Natto

1. Selecting soybeans: Use domestic organically grown soybeans preferably of the small variety where possible. Remove insect bitten, damaged or discoloured beans. Wash 2 cups of soybeans with fresh water, try not to damage any beans while washing.
   
   
2. Soak soybeans in 6 cups of water for 12 hours, or overnight [8 to 9 hours during summer].
   
   
3. Steaming/boiling beans: After soaking, strain beans and steam in a pressure cooker by adding 2 cups of water in the cooker, and placing a steam rack at the bottom of the cooker, making sure that the surface of the steam rack is above the water level. Add the beans into the cooker, on the steam tray and pressure cook for 1 hour.
   
   Or Boil: Boil soy beans with 6 cups water, boiling for 8 to 9 hours. Check beans every 2 hours to make sure that the beans are covered with water, adding more water when necessary. The beans should be cooked until they easily crush when a bean is lightly squeezed between the fingers [they should be well cooked].
   
   
4. Inoculation: Strain cooked beans and cool to body temperature. Place the beans in a clean deep pre sterilized bowl [sterilize by pouring boiling hot water into the bowl, and then pouring the water out]. Measure ½ tsp of Natto spore starter powder with supplied plastic spoon, and mix with 2 Tbs of pre-boiled and cooled water. Pour the starter solution over the beans and mix well to evenly disperse the starter.
   
   
5. Filling containers with inoculated beans: For practicality, use flat containers for fermentation. Fill the container with a thin layer of inoculated soybeans, to app. 2 cm [app. 1 inch] in depth. Place a sterilized white cotton or linen cloth over the surface of the beans, then seal the try with either a sheet of aluminium foil, or cling-wrap plastic film.
   
   
6. Fermenting Natto: Incubate the beans between 38º C to 40º C, and leave for 22 to 24 hours.
   
   
7. Aging Natto: After fermentation, remove the foil or cling-wrap from the container and place the tray in a refrigerator with the cloth left in place over the beans. Refrigerate overnight before consuming.

Natto can be frozen for up to 2 months, by placing natto in freeze plastic bags, or in a suitable container. An amount of fresh of frozen natto may be used to inoculate more cooked soybeans, by using app. 5% to 10 % natto to well cooked soybeans, using natto in place of the starter in step 4 above. But do not use natto frozen for longer than 2 months .

Japanese Instructions by Yuzo Takahashi Laboratory

English Translation

Japanese Nattomoto Spore Starter

Created by Dominic N. Anfiteatro October 20, 2004

Updated October 6, 2005

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