How to Make Natto Without a Commercial Starter

While making natto typically involves using a starter culture, it's possible to replicate this fermented soybean dish using alternative methods. This guide will walk you through the process of making natto without a commercial starter, using natural fermentation techniques.

Ingredients

Soybeans: 1 cup or more, depending on your desired yield Water: For soaking and cooking Equipment: A steamer or pot A container for fermentation, such as a glass jar A warm environment, around 100°F (38°C)

Steps

Soak the Soybeans Rinse the soybeans thoroughly and soak them in water for 8-12 hours or overnight. This helps to soften the beans. Cook the Soybeans Drain the soaked soybeans and cook them until they are very soft. You can steam them for about 30-60 minutes or boil them until tender. Ensure they are fully cooked, as this is crucial for fermentation. Cool the Soybeans Allow the cooked soybeans to cool to around 100°F (38°C). This temperature is ideal for fermentation. Introduce Natural Cultures Rather than using a commercial starter, you can use a small amount of store-bought natto that contains live cultures, or find a local source of koji (Aspergillus oryzae) that might be available in Asian markets. Contact your local Asian market or online Asian grocery store to source koji. Add about 1 tablespoon of the store-bought natto or 1-2 teaspoons of koji to the cooled soybeans and mix well. Fermentation Transfer the mixture to a clean container. Cover it with a lid or cloth, allowing some air circulation but preventing contamination. Place the container in a warm environment maintained at around 100°F (38°C) for 24-48 hours. Use an oven with the light on, a yogurt maker, or an insulated container to maintain the temperature. Check for Fermentation After 24 hours, check the natto. It should have developed a sticky texture and a strong, distinctive smell. If it hasn’t fermented enough, you can leave it for another 12-24 hours. Storage Once fermented, transfer the natto to the refrigerator to slow down the fermentation process. It can be stored in the fridge for up to a week.

Tips

Sanitation: Ensure all equipment is thoroughly cleaned and sanitized to prevent unwanted bacteria. Temperature Control: Maintaining a consistent temperature is crucial for successful fermentation. Use insulation and temperature control methods like an oven with light on or a yogurt maker to achieve this. Experimentation: If you find the flavor or texture not to your liking, adjust fermentation times or temperatures in future batches. This process can be unpredictable, so some trial and error may be involved.

Note: While you can make natto without a starter using a small amount of existing natto or koji significantly increases your chances of success. The natural fermentation process can be unpredictable without these cultures, so some trial and error may be involved.