How to make natto. Discover the secrets of this delicious food.

How to make natto. Discover the secrets of this delicious food.


What is natto?

You may or may not have heard about natto, a fermented food that is very common in Japan. Natto has a unique and surprising smell. Enjoying the taste of natto is said to be acquired. Natto is highly nutritious and is associated with several health benefits, a healthier heart, a more resilient immune system and stronger bones. This food is a traditional Japanese dish comprising fermented soybeans and has a slimy texture. It usually tastes nutty and has a pungent smell. Natto in Japan is usually consumed with soy sauce and mustard, along with cooked rice. 

Natto in a bowl and how to make natto

How can you make natto?

In the past, natto was made by wrapping boiled soybeans in rice straw that contained the bacteria Bacillus subtilis (B. subtilis) on its surface.Hence the bacteria could ferment the sugars in the beans. Natto is a product of this fermentation process. 

At the start of the 20th century, the B. subtilis was isolated by scientists who modernised this fermentation approach. 

Typically in modern times, styrofoam boxes have replaced rice straws in which B. subtilis can be applied to boiled soybeans to kickstart fermentation.

Health Benefits of Natto: It is rich in nutrients

A 3.5-ounce (100-gram) portion of natto contains :

  • Calories: 212
  • Fat: 11 grams
  • Carbs: 14 grams
  • Fiber: 5 grams
  • Protein: 18 grams
  • Manganese: 76% of the RDI
  • Iron: 48% of the RDI
  • Copper: 33% of the RDI
  • Vitamin K1: 29% of the RDI
  • Magnesium: 29% of the RDI
  • Calcium: 22% of the RDI
  • Vitamin C: 22% of the RDI
  • Potassium: 21% of the RDI
  • Zinc: 20% of the RDI
  • Selenium: 13% of the RDI

Moreover, natto has smaller amounts of antioxidants, vitamin B6 and folic acid. Furthermore, natto also has greater amounts of beneficial plant compounds and enzymes than non-fermented soybeans. 

When the soybeans in natto are fermented, conditions that encourage the growth of probiotics are created. Probiotics make foods more digestible for better absorption of nutrients.One gram of natto contains almost the equivalent amount of probiotics as an entire serving of many other probiotic-rich foods or supplements.The probiotics in natto can protect your body against toxins and harmful bacteria. Studies have reported that probiotics can decrease gas, constipation, antibiotic-associated diarrhea and bloating, symptoms of inflammatory bowel disease (IBD), Crohn’s disease and ulcerative colitis. Besides, soybeans naturally contain antinutrients that make it challenging for your body to digest them. Antinutrients can also decrease the amount of nutrients your body absorbs from foods and may lead to nausea or bloating. Thankfully, natto fermentation helps decrease the levels of antinutrients that are naturally found in soybeans, facilitating food digestion [1].

Natto strengthens healthy bones

A 3.5-ounce (100-gram) portion of natto contains 22% of the recommended daily intake (RDI) of calcium. Calcium is the primary mineral found in your bones. Vitamin K2 is also found in natto. This vitamin activates bone-building proteins that bring calcium to your bones. Studies depict vitamin K2 supplements in slowing down age-related loss in bone mineral density [2]. That being said, although eating natto can increase your vitamin K2 levels, whether eating natto solely would offer the same amount of health benefits remains to be seen. 

Natto may enhance your heart health

Additionally, natto fermentation produces nattokinase, an enzyme that dissolves blood clots. Nattokinase appears to be concentrated in the “stringy portion” of natto [1]. Researchers have asserted that natto may aid in reducing blood pressure by inactivating angiotensin converting enzyme (ACE). ACE aids in regulating blood pressure [3]. Also, the vitamin K2 in natto prevents the accumulation of calcium deposits in your arteries [4]. 

Where You Can Buy Natto in Singapore

Purchase your natto from places like Craft&Culture Singapore, and even at NTUC Fairprice. 


[1] A. Petre, “Why natto is super healthy and nutritious,” Healthline, 31-Mar-2017. [Online]. Available: [Accessed: 18-Aug-2022]. 

[2] Knapen MH;Drummen NE;Smit E;Vermeer C;Theuwissen E; “Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women,” Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. [Online]. Available: [Accessed: 18-Aug-2022]. 

[3] Kim JY;Gum SN;Paik JK;Lim HH;Kim KC;Ogasawara K;Inoue K;Park S;Jang Y;Lee JH; “Effects of nattokinase on blood pressure: A randomized, controlled trial,” Hypertension research : official journal of the Japanese Society of Hypertension. [Online]. Available: [Accessed: 18-Aug-2022]. 

[4] M. S. El Asmar, J. J. Naoum, and E. J. Arbid, “Vitamin K dependent proteins and the role of vitamin K2 in the modulation of vascular calcification: A Review,” Oman medical journal, May-2014. [Online]. Available: [Accessed: 18-Aug-2022]. 


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