Natto divides Japan. People who grew up eating it find the flavor comforting — the smell of morning, of fermentation, of home. People who didn't grow up eating it often struggle. The smell is strong. The texture is viscous. The taste is complex in a way that rewards repeated exposure rather than immediate approval.
This is not a flaw. It's fermentation doing what fermentation does.
What Natto Is
Natto is soybeans fermented with Bacillus subtilis natto — a bacterium that produces enzymes which break down the soybean proteins over 24-48 hours of incubation at around 40°C. The result:
- Texture: sticky, with characteristic stringy threads (neba-neba) that form when you lift the beans
- Flavor: earthy, ammonia-tinged (from protein breakdown), nutty, deeply umami
- Smell: pungent, fermented, somewhat similar to aged cheese
The strings are structural — the more you stir natto, the more pronounced the threads become and the more the flavor mellows slightly. This is not a food quirk: stirring is the correct technique.
Why Eat Natto
The nutritional profile is exceptional:
- Very high in protein (17g per 100g serving)
- High in fiber
- Rich in vitamin K2 (MK-7 form) — uncommon in most diets and important for calcium metabolism and cardiovascular health
- Contains nattokinase (an enzyme thought to support cardiovascular health — though the research is ongoing)
- Probiotic — fermented food with live cultures
It's cheap (¥60-100 per serving in Japan; $2-4 per package outside), quick to eat, requires no cooking, and keeps well refrigerated.
These are the reasons natto remains a staple of the Japanese breakfast despite being an acquired taste.
The Standard Preparation
Natto in Japan is sold in styrofoam containers (typically 45g per unit, 3 per pack) in the refrigerator section of any grocery or convenience store. Each package includes small packets of soy sauce and karashi (Japanese mustard).
The correct technique:
- Open the package. Remove the thin film covering the beans (there's a pull tab).
- Add the soy sauce and mustard packets.
- Stir vigorously — 50-100 strokes with chopsticks or a fork. This is not an exaggeration. You are developing the neba-neba texture, incorporating air, and mellowing the flavor. The threads should become white and thick, almost fluffy. Under-stirred natto is harsher in flavor; properly stirred natto is creamier and less aggressive.
- Serve over hot steamed rice. The heat of the rice warms the natto slightly.
Standard additions:
- Thinly sliced green onion — brightens and adds freshness
- Karashi (Japanese mustard) — already in the packet; use it, it cuts through the richness
- Raw egg yolk — yolk only, mixed into the natto. This is a common variation, especially in natto gohan (natto rice bowl). The yolk adds richness and rounds the flavor.
- Soy sauce — the included packet is the correct amount; add more to taste
The Breakfast Bowl (Natto Gohan)
The standard way to eat natto in Japan:
- Cook Japanese short-grain rice.
- Prepare natto as above: stir 50-100 times with soy sauce and mustard.
- Add sliced green onion.
- Place on a bowl of hot rice.
- Optional: add a raw egg yolk on top, a small amount of sesame oil, or a few drops of additional soy.
Eat by mixing the natto into the rice as you go, or leaving them separate and eating from each section of the bowl. Both approaches exist; mixing in is more common.
Cost: approximately $1-2 total per serving including rice. Fast, nutritionally complete, protein-rich. The perfect weekday breakfast.
Making It More Accessible
For first-timers, these combinations reduce the confrontational elements:
Natto + kimchi: The assertive flavor of kimchi meets and partially masks the natto while complementing the fermentation note. Both are fermented, which creates harmony rather than conflict. Add both to rice; stir together.
Natto + avocado: Avocado's fat and creaminess smooths the sharpness. Mash half an avocado, mix with prepared natto, serve on rice or toast. This is a gateway version that works for people who are natto-curious.
Natto maki (sushi roll): Natto wrapped in rice and nori with a little cucumber. The rice and nori frame the natto and make it less intense. This is a common beginner exposure in Japan — less confrontational than a full bowl.
Natto pasta: A modern Japanese fusion preparation — natto tossed with spaghetti, butter, soy sauce, and nori. The carbs and butter buffer the intensity; the savory umami quality reads as pasta seasoning rather than fermented bean.
The Smell
The smell is the main barrier. It contains isovaleric acid and other volatile compounds produced during fermentation — the same compounds in aged cheese and some wines. If you can eat a strong blue cheese without distress, the smell of natto is comparable in intensity.
Practical note: the smell is much stronger than the taste. Newcomers who manage to eat past the smell typically find the actual flavor less confrontational than expected.
If the smell is the issue: eat it cold (not warmed — warming intensifies the smell), stir thoroughly to incorporate air, eat quickly rather than slowly, and pair with strongly flavored companions (kimchi, strong soy sauce, green onion).
Buying Natto
Japan: Any convenience store or supermarket. Refrigerator section, 3-pack styrofoam containers.
Outside Japan: Japanese grocery stores (Mitsuwa, H Mart, most Asian grocery stores with Japanese sections). Also available on Amazon in frozen form (freeze-dried natto lacks some of the living culture but has similar flavor). Some Korean grocery stores also carry it.
Brands: Mizkan, Takanofoods (Okame natto), and various regional Japanese brands. The beans vary in size (hikiwari — small beans crushed, easier to eat; regular; extra-large beans that intensify the experience). Start with regular or hikiwari.
Making Natto at Home
Possible but not necessary since commercial natto is cheap and widely available. The process: cook soybeans, inoculate with Bacillus subtilis natto starter (available online), incubate at 40°C for 24-48 hours. Requires a yogurt maker, Instant Pot on yogurt setting, or a DIY incubation setup.
Home natto tends to be stronger in flavor than commercial natto, which is precisely calibrated.
The Fusion Angle
Natto represents Japan's long tradition of soybean fermentation — a tradition that parallels East and Southeast Asian fermentation cultures (Korean doenjang, Chinese doubanjiang, Indonesian tempeh). Where Western fermentation culture focuses on dairy (cheese, yogurt) and alcohol, East Asian fermentation culture developed around soybeans and grains.
Tempeh — Indonesian fermented soybeans — is the closest equivalent to natto in terms of process and nutritional profile. Both use whole soybeans fermented with a specific microorganism. Tempeh uses a mold (Rhizopus oligosporus) and produces a firm cake; natto uses a bacterium and produces loose, sticky beans. The flavor profiles are completely different, but the underlying logic — nutrient-dense, cheap protein preserved through fermentation — is the same.
Natto is Japan's tempeh. If you've eaten tempeh and liked it, natto is worth the attempt.
The full recipes live in the book.
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