How to Make Nattō: 3 Ways to Eat Fermented Soybeans

Japanese nattō are soybeans fermented with the bacteria Bacillus subtilis var. Nattō. This traditional food from Japanese cuisine is known for its gelatinous, sticky texture, similar to okra, and a pungent, nutty smell akin to aged cheese.

Eating nattō as part of a balanced diet has many proven health benefits. The fermented superfood contains probiotics that assist in digestive health and boost the immune system. Nattō is also rich in vitamins and minerals such as calcium, magnesium, vitamin K1, and vitamin K2—all of which play a crucial role in bone health.

Nattō tastes slightly different on every palette—some describe it as earthy bitterness, while others pick up notes of musty tang reminiscent of Roquefort cheese. When stirred vigorously with chopsticks, the polyglutamic acid produced through the fermentation process creates nattō’s signature sticky web-like texture.

There are many ways to eat nattō. For cooking, there’s hikiwari nattō, crushed beans with a smoother, more flexible texture. Kotsubo nattō, which features the whole fermented bean, makes a perfect standalone dish or condiment. Here are few other ways to enjoy the traditional fermented food:

1. 1. As breakfast. Nattō served over white rice with soy sauce, sliced green onions, and karashi (hot Japanese-style mustard), or a swatch of wasabi, is common breakfast food in Japan. Most of the nattō that you may find in Asian grocery stores comes with individual seasoning packets of mustard and soy sauce, sometimes flavored with katsuobushi (dried bonito flakes) for extra depth and a boost of umami.
2. 2. In sushi. Nattōmaki pairs nattō with seasoned sushi rice and chives, all wrapped in a sheet of nori for a quick lunch or dinner.
3. 3. As a condiment. You can spread nattō on toast, incorporate it into okonomiyaki (savory Japanese pancake), or onigiri (steamed rice balls with a savory filling), or mix it into ramen, miso soup, or soba noodles, where its tang and bitterness complement richer flavors.

Homemade nattō requires a specific bacterial culture and immaculate fermentation conditions, so it is typically purchased pre-made, but it’s a relatively simple process. You can find powdered nattō starters online and in some specialty stores.

• First, wash and soak the beans. Rinse 2 cups of raw soybeans and soak in cold, clean water for anywhere from 12–24 hours until they double in size.
• Then, steam the soaked beans. Using a steamer basket or pressure cooker, steam the beans until they can be easily crushed between your fingers but still hold their shape, just under 1 hour. Let them cool slightly.
• Sterilize all equipment. Before introducing the nattō starter, ensure every piece of equipment has been sterilized in boiling water—from the container you’ll be using to any utensils.
• Inoculate the cooked beans with nattōkin. Add the steamed soybeans to a large glass baking dish and sprinkle in ¼ teaspoon of nattō starter. Carefully mix to distribute evenly.
• Ferment for 24 hours. Cover the container tightly with plastic wrap while still warm, and let it sit at room temperature for 24 hours.
• Transfer to the refrigerator for aging. Place the nattō in the refrigerator for one week, where it will continue to ripen. Stir well when ready to use.

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