The Complete Guide to Natto

Natto is a traditional Japanese food made from fermented soybeans. Known for its distinctive sticky, stringy texture and strong flavor, natto is a nutritional powerhouse packed with protein, vitamins, and the enzyme nattokinase.

What You'll Need

Equipment

• Pressure cooker or Instant Pot
• Incubator (oven with light, dehydrator, or yogurt maker)
• Shallow containers with lids
• Thermometer
• Sterilized spoon

Ingredients

• 2 cups dried soybeans (organic preferred)
• Natto starter (Bacillus subtilis spores)
• Filtered water

Basic Natto Recipe

Step 1: Prepare Soybeans

1. Rinse soybeans and soak for 12-24 hours
2. Beans should double in size
3. Drain and rinse well

Step 2: Cook Soybeans

1. Pressure cook for 45 minutes until very soft
2. Beans should crush easily between fingers
3. Drain, reserving some cooking liquid

Step 3: Inoculate

1. Let beans cool to 115°F (46°C)
2. Dissolve natto starter in 2 tablespoons warm water
3. Sprinkle over beans and mix gently
4. Work quickly to maintain temperature

Step 4: Ferment

1. Spread beans in shallow containers (1 inch deep max)
2. Cover loosely - natto needs oxygen!
3. Maintain 100-115°F for 22-24 hours
4. Check for white, stringy threads

Step 5: Mature

1. When threads appear, fermentation is complete
2. Refrigerate for 24 hours to develop flavor
3. Natto improves over 2-3 days in the fridge

Signs of Successful Natto

• White, powdery coating on beans
• Sticky, stringy threads when stirred
• Earthy, slightly ammonia-like aroma
• Beans are soft but intact

Common Issues

No strings forming?

• Temperature too low or inconsistent
• Starter may have been added when too hot
• Beans not soft enough before inoculating

Ammonia smell too strong?

• Fermented too long
• Temperature was too high
• Still safe to eat, just more pungent

Slimy but no strings?

• Contamination possible
• Ensure all equipment was sterilized

How to Eat Natto

Traditional serving:

1. Add soy sauce and mustard
2. Stir vigorously until very stringy
3. Serve over hot rice

Other ideas:

• Mix into pasta
• Add to miso soup
• Spread on toast with avocado
• Blend into smoothies (really!)

Health Benefits

Natto is exceptionally nutritious:

• Nattokinase: Enzyme that supports cardiovascular health
• Vitamin K2: Important for bone health
• Complete protein: All essential amino acids
• Probiotics: Beneficial bacteria for gut health
• Easy to digest: Fermentation breaks down proteins

Next Steps

• Learn to make your own natto starter
• Try black bean natto
• Explore natto recipe ideas