Natto
Natto is a traditional Japanese food made by fermenting soybeans with Bacillus subtilis, known for its distinctive sticky strands and pungent aroma, and a leading example of fermented vegetarian fare rich in nattokinase.
Nutrition
Natto contains about 18 grams of protein per 100 grams. During fermentation, soy protein is partly broken down into amino acids and peptides that are easier for the body to absorb, while the process also generates nattokinase and abundant vitamin K2, making natto a distinctive fermented food among soy products.
How to Choose
Good natto has plump, evenly sized beans, a light brown color, and stringy, sticky threads that are smooth and fine throughout. It should smell like natural fermentation rather than a sharp ammonia odor. When buying refrigerated packaged natto, check the production date and shelf life.
Cooking
After opening, stir natto until the sticky strands turn smooth and even for the best flavor. It can be eaten as is, mixed with soy sauce, mustard, and chopped scallions, or stirred into rice, noodles, or a natto miso soup. Because the fermentation bacteria are sensitive to heat, natto shouldn't be cooked for long periods.
Storage
Natto must stay refrigerated at all times; once opened, eat it within 1-2 days. It can also be frozen to extend its shelf life — just move it to the refrigerator to thaw naturally before eating, with little change in flavor.
Tips
First-time eaters of natto often need a moment to adjust to its distinctive smell and sticky texture. Start with a small amount stirred into rice, and add soy sauce, mustard, and chopped scallions to soften the impact of its flavor. The longer and more evenly fine the sticky strands stretch, the more thoroughly fermented the natto generally is — and the higher its nattokinase activity — which makes stringiness a handy visual gauge of quality.
