Natto
Ingredients
Directions
Prepare the soybeans
Wash the soybeans.
Soak the soybeans for 9–12 hours (longer soaking time recommended during colder months).
Use approximately 3 parts water to 1 part soybeans to allow for expansion.
You will have 8–12 cups of beans.
Drain the beans from the soaking water.
Place beans in a large pot, fill with water and boil for 9 hours.
Drain the cooked beans and place in a sterilized pot.
Inoculate and pack
Dissolve one special spoonful of nattomoto into 2 tsp of sterilized water.
Immediately pour the nattomoto solution over the beans while the beans are still warm.
Stir the beans and water mixture together carefully using a sterilized spoon.
Place a thin layer of beans in each of the 3–4 containers.
If at any point during the process some beans are spilled on the counter, discard the spilled beans as they can contaminate the other beans if added back in to the batch.
Place the sterilized cheese cloth over the top of the containers and place the tight-fitting lid over the cheese cloth.
Ferment and chill
Preheat the oven, dehydrator, or KOTATSU Japanese Warmer to 100°F (38°C).
Place the covered containers in the oven, dehydrator, or warmer and allow the natto to ferment for 22–24 hours, making sure to keep the temperature steady at 100°F (38°C).
At the conclusion of the fermentation period, let the natto cool for a couple of hours.
Remove the lid and the cloth, replace the lid, and store the containers in the refrigerator at least overnight.
The Natto can be consumed as early as the next morning and are often served as a Japanese-style breakfast.
Steps grouped into stages for easier reading; the method is the source's own.
Explore the science
What each ingredient does
- Soybeans
- The main ingredient; soaking and boiling soften them so the bacteria can ferment them.
- Nattomoto powder
- Starter culture containing Bacillus bacteria that ferment the beans into natto.
The step that matters
Keeping the fermentation temperature steady at 100°F (38°C). The Bacillus culture ferments best at a steady warm temperature. Drops in heat can slow or stall fermentation, while the spilled-bean warning reflects the risk of contamination spreading unwanted microbes through the batch.
“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.
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