Perhaps no other food in Japanese cuisine is as notorious as natto or fermented soybeans. With its strong ammonia smell and sticky, stringy texture, natto is either devotedly revered or intensely disdained. There seems to be no lukewarm reaction to natto.
The origin of natto is unclear with several theories but a legend tells about how the serendipitous invention made when the army of Hachimantaro, a Minamoto clam samurai in the Heian Period, was under attack and had to quickly pack up boiling soybeans in straw bags. When they opened the bags days later, they ate the spoiled beans and found they liked the flavor. Because soybeans and straw were common, it is likely that farmers also discovered this food.
Today, natto is made from soybeans that are cooked then infused with a starter culture, a strain of bacteria called Bacillus subtilis (also known as Bacillus natto). After fermenting for 24 hours, it is aged in a cooler for about a week as the enzymes break down the protein which develops its stringy nature.
If it is as repulsive as so many attest then why it natto so popular? Natto is to the Japanese as lutefish is to the Scandinavian and haggis to the Scotts. Even among the Japanese, people seem to be divided among those who eat natto and those will do not. Foreigners often are regarded with more respect if they can appreciate strong foods like natto or uni (sea urchin gonads).
For years, I would not try natto. My husband could not understand my hesitation when I love other smelly foods like rakkyo (pickled scallions) and takuan (pickled daikon radish) which repel him. So, I decided to be more open-minded and give natto a try. When I opened up a small box, I expected to be hit with an overpowering odor. But I had to stick my nose in closer to detect a slight cheesey aroma. It was not unpleasant. The matted mass reminded me of rice cereal treats during the cooking stage when the melted marshmallows get stringy. Not too appetizing.
I managed to drop some into a chawanful of hot white rice. The box came with tiny packets of karashi hot mustard and soy sauce which I blended and placed on the natto. Reminding myself that I like tamago meshi with its half-cooked texture, I lifted my chopsticks to my mouth and slipped in the natto rice. Surprise. There is something about the combination of natto over steamed rice, karashi (hot mustard) and sweet soy sauce that tastes delicious!
There are many smelly foods that we come to love like strong bleu cheese, fish and onions. What we love is a matter of what we have been exposed to and accustomed to at an early age when we are more open-minded about new smells and flavors.
Natto lovers are known to spread natto on toast or drop blobs of natto into bowls of ramen, curry or spaghetti. It adds a distinctive tangy flavor they love.
How to eat natto
The customary way to enjoy natto is to eat it on some hot rice. Most people blend a little soy sauce or other condiments like sliced green onions, grated daikon radish and hot mustard (karashi) into the natto first. Because it is easy to open up a package of natto, it is eaten on busy mornings as a breakfast food, quick lunch, savory snack or light dinner. It is said to be highly nutritious with great medicinal benefits. You will have to investigate such claims yourself. Until then, simply enjoy this centuries-old food as a delicious meal.