Natto, the popular Japanese dish made from fermented soybeans, isn’t exactly pretty to look at. Its smell might not be all that enticing either. However, it is one of the healthiest dishes consumed in Japan and is considered a superfood. Those seeking to eat healthily, vegetarian, or simply wishing to enjoy tasty cultural dishes all enjoy natto, even though it can mainly only be found in Asian supermarkets in the United States.
But if you don’t have a nearby Asian supermarket selling natto, you can easily make your own at home. The process is not difficult, and the equipment and ingredients needed are not overly complex either.
Cooking Equipment Needed to Make Homemade Natto
To make natto, it is likely that you already have all the cooking supplies you need. These include a stainless steel or enameled pot, a large stainless steel spoon, 3-4 glass, oven-proof containers with lids, and cheesecloth. All equipment should be sterilized before using—the utensils can be boiled for five minutes before you are ready to use them, and sterilized cheesecloth can be purchased as well.
Ingredients Needed to Make Homemade Natto
All you need is 4 cups of soybeans and a special type of fermenting spores, called natto spores, Bacillus natto bacteria powder, or Nattamoto powder. This is the culture that will be used to ferment the soybeans.
Some recipes might show you some tricks to create a yeast starter culture without using the Bacillus culture, but for a true natto, seek to purchase the spores online. Most of the packages come with a small spoon enabling you to easily measure how much of the bacterial yeast you will need to add to the soybeans to begin the fermentation process.
How To Make Your Own Homemade Natto
- To begin, wash the soybeans with a strainer, and then soak them in water for 24 hours.
- Steam the soybeans for approximately 3-6 hours, stopping when they can be easily crushed with your fingers. Drain the soybeans.
- Be sure that all utensils and dishes are clean and sterile, as well as your hands. This ensures that no other bacteria interfere with the fermentation process. Pour the soybeans into a sterilized bowl.
- Mix 1 spoonful (0.1 grams of Bacillus natto bacteria powder with 2 tablespoons of boiled water until it dissolves. Pour the mixture over the soybeans and stir until well-mixed.
- Transfer the beans to the sterilized, oven-safe dishes. Spread the beans in a thin layer, no more than 1 inch high.
- Place a sterilized linen cloth or cheesecloth over the dishes, and secure the lids over the cloth and the dish.
- Put the dishes in the oven and set at a temperature of 100°F. If your oven doesn’t enable a low-temperature setting, simply turn on the oven light. This should provide just enough heat for fermentation. The ideal temperature is anywhere between 99-108°F. After a short while, use a thermometer to check the temperature in the oven. If it isn’t warm enough, you can try adding a small, battery-operated work lamp to bring up the heat.
- Remove the dishes from the oven, allow to cool, remove the cloth, and refrigerate the dishes overnight.
The natto can be stored in the refrigerator for up to one week, and can also be frozen for up to two months. Also, keep in mind that when making your own natto, the fermentation process can give off a strong odor.