Natto: Japan's Most Divisive Food
Natto stands apart in Japanese cuisine as perhaps the most polarizing food—adored by locals and many adventurous tourists, passionately rejected by others. It's fermented soybeans with a distinctive stringy texture, pungent ammonia-like aroma, and intensely umami flavor that challenges expectations about what food should be.
For many Japanese people, natto is pure comfort—spooned over rice at breakfast, added to sushi, or featured in pasta dishes. For first-time tasters, it's often confrontational, inspiring strong reactions ranging from fascination to immediate rejection.
What Is Natto? The Science Behind the Slime
Natto is soybeans fermented using Bacillus subtilis, the same bacteria used in other fermented foods worldwide. The fermentation process creates:
- Natto kinase: An enzyme believed to have blood-thinning properties
- Mucopolysaccharides: Complex sugars responsible for the stringy texture
- Volatile compounds: Ammonia-like aromas and intense umami flavors
The fermentation process takes approximately 24 hours at controlled temperature. The resulting natto is packaged fresh and typically kept refrigerated, with a shelf life of 1-2 weeks. Natto can be frozen, extending shelf life indefinitely, though texture changes slightly after thawing.
The Natto Experience: Smell, Texture, Taste
Aroma
The smell is perhaps the most challenging aspect of natto. The ammonia-like, pungent odor is stronger than most Western palates expect. It's not unpleasant—more unfamiliar. The aroma comes from volatile organic compounds produced during fermentation. Cooked or warm natto has less pungent aroma than cold natto straight from the refrigerator.
Texture
The distinctive stringy texture comes from the bacteria's byproducts. When you stir natto, it becomes increasingly stringy—you can stretch it between fork and spoon creating long, slimy strands. This texture is intentional and celebrated in Japan, but it's often the primary barrier for Western eaters accustomed to firmer textures.
Taste
Natto tastes deeply umami-rich, salty, and slightly sweet. The flavor is subtle until you taste it with rice, where it becomes more pronounced. Fresh natto has cleaner flavor; older natto becomes more pungent and ammonia-forward.
How to Eat Natto: Proper Technique
Classic: Natto over Rice
- Place warm steamed rice in a bowl
- Add natto (usually a single packet)
- Add soy sauce to taste (often provided with natto)
- Add optional condiments (scallions, wasabi, nori)
- Stir vigorously for 30-50 seconds until completely incorporated
- The stirring is crucial—it distributes the strings and creates a silky consistency
The rice should appear glossy and well-coated. Eat immediately while rice is warm.
Natto in Other Preparations
- Natto pasta: Mixed with butter, soy sauce, and pasta for a savory, umami-rich dish
- Natto sushi rolls: Inside rolls or scattered on top after rolling
- Natto noodles: Added to udon or soba broths
- Natto on toast: Spread on bread with butter for unexpected breakfast
- Natto in tamago: Mixed into tamagoyaki (sweet egg rolls)
Natto Quality and Selection
Premium natto costs ¥500-2,000 per pack, while standard supermarket natto costs ¥100-300. Differences include:
- Bean size: Larger, uniform beans suggest higher quality
- Fermentation duration: Longer fermentation (5-7 days) creates more pungent flavor; shorter fermentation (1-2 days) creates milder versions
- Processing: Organic certification, specific bacterial strains, and brewing methods affect quality
- Packaging: Premium natto comes in traditional wooden boxes; standard natto uses plastic cups
For first-time tasters, milder varieties are more approachable. Mild natto (especially young natto fermented only 1-2 days) has cleaner flavor and less ammonia aroma. Aged natto becomes progressively more challenging.
Regional Variations
Ibaraki Prefecture Natto
Ibaraki is Japan's natto capital, producing approximately 70% of the nation's natto. Local varieties tend toward traditional fermentation and robust flavor. Ibaraki stations feature natto products prominently.
Kumamoto Natto
Uses different bacterial strains creating slightly sweeter, milder profiles compared to standard varieties.
Hirado Natto
An Nagasaki specialty featuring small soybeans and distinctive fermentation creating a different texture and aroma.
The Health Claims
Japanese health culture associates natto with longevity and wellness:
- Natto kinase: Purported to reduce blood clots and support cardiovascular health
- Probiotics: Beneficial bacteria may support digestive health
- Vitamin K2: Natto is a superior source of this nutrient, important for bone health
- Umami compounds: May support overall nutrition
Scientific research supports some (but not all) traditional health claims. Natto is definitely nutritious, but it's not a miracle food. That said, including natto in a balanced diet doesn't hurt and may offer measurable benefits.
Tips for First-Time Natto Eaters
Start with mild natto: Young natto or specifically labeled "mild" varieties are more approachable than aged varieties.
Warm it first: Heating natto slightly reduces the pungent aroma and makes the texture less confrontational. Microwave for 20-30 seconds or add to hot rice immediately.
Pair strategically: The umami in natto pairs beautifully with:
- Salty condiments (scallions, wasabi, soy sauce)
- Acidic elements (vinegar, lemon)
- Rich carbohydrates (rice, pasta)
- Crispy textures (nori, panko)
Stir aggressively: The more you stir, the better the texture and distribution.
Manage expectations: Natto isn't supposed to taste "good" in the traditional sense—it's meant to be challenging, interesting, and flavorful in unfamiliar ways. Approaching it with curiosity rather than expectation improves the experience.
Try multiple times: Many natto skeptics become enthusiasts after several exposures. The acquired taste isn't immediate for everyone.
Where to Eat Natto
Convenience stores (Lawson, FamilyMart, 7-Eleven) sell natto packets in the refrigerated section. Cost is ¥100-200; instructions are usually pictured on packaging.
Dedicated natto restaurants exist in Ibaraki and major cities, offering natto-focused menus.
Sushi restaurants often feature natto rolls and gunkan-maki (rice boats topped with natto).
Breakfast sets at casual restaurants include optional natto additions.
Natto at Home
Natto is easy to incorporate into your own cooking:
- Buy fresh natto from Japanese grocery stores in your country (if available)
- Mix with pasta and butter for quick dinner
- Add to rice bowls with soy sauce and scallions
- Include in sushi rolls
Alternatively, natto cultures are available online for those interested in fermenting their own soybeans.
The Verdict: Natto as Gateway Food
Natto represents a challenge and an opportunity—to expand your palate, try something genuinely unfamiliar, and understand Japanese food culture's embrace of umami and acquired tastes. You don't need to love natto, but trying it with an open mind and proper technique is worthwhile.
Whether you become a devoted enthusiast or decide it's not for you, attempting natto is an authentic Japanese culinary experience that bridges food adventure and cultural understanding.
