For Natto Lovers Outside Japan! Home-Made Natto in an Oven!

For Natto Lovers Outside Japan! Home-Made Natto in an Oven!

Natto can be made at home, so you don't have to go without it even when living abroad. I've been making this for 3 years. I'm continuing to experiment on a daily basis, always aiming for even tastier natto. I make a batch of natto every 1-3 months.

Ingredients: approx. 20 servings

Soy beans (organic)
500 g
Natto bacteria
0.3 g
Pressure cooker, pressure cooker steaming basket, paper towels, spoon, and storage containers with sieve inserts


1. Wash the soy beans well, and soak in plenty of water for 15 hours.
2. Pour at least 600 ml of water to the steaming rack, and insert the steaming basket. Wrap the soy beans in a bleached cotton cloth/cheesecloth, and place in the steaming basket. Steam in the pressure-cooker (30-40 minutes over medium heat after the cooker reaches pressure).
3. In the meantime, sterilize the following equipment in boiling water: containers with sieve inserts the lid of a pot spoon.
4. Allow the pressure cooker to de-pressurize naturally (natural release method), and using a tongs remove the wrapped soy beans. Place in the sterilized lid.
5. Leave 25-50 ml of the steaming liquid in the bottom of the pressure cooker pot. Add about 0.3 g (3 spoonfuls of the tiny spoon that comes with the natto kin; it's best to be generous) of the natto kin and mix to dissolve.
6. Add the Step 4 steamed soy beans back to the pressure cooker pot. Shake the pan around to thoroughly mix the beans with the natto kin.
7. Using the Step 3 sterilized spoon, fill the sterilized sieve inserts of the steralized containers with the beans to about 2 cm below their rims. Cover each container with a paper towel, and then seal with the lids or plastic wrap. Don't seal so that they are airtight and leave a little gap.
8. Ferment the beans in an oven at 38-42°C. Set the temperature using the oven light, a fluorescent bulb, or a bowl filled with hot water.
9. If you put the beans too close to the bulb, they'll dry out so, so be careful. Make sure the paper towels don't touch the beans. Change the paper towels halfway through the fermentation process.
10. 24 hours later, if the surfaces of the soy beans are completely covered with white spores and are sticky, the natto is done.
11. Wipe off any condensation from the lids, cool the beans down and store in the freezer.
12. To defrost, microwave for 20 seconds.

Story Behind this Recipe

This recipe is for those who love natto and want to eat it regularly, but can't because it's expensive where they live!