How to Ferment Doubanjiang
How to Ferment Doubanjiang: The Heart of Sichuan Flavor
Doubanjiang, also known as "Chinese fermented broad bean paste" or "Sichuan chili bean paste," is a key ingredient in Sichuan cuisine, renowned for its bold, savory, spicy, and slightly funky flavor. This fermented paste is made from broad beans (also called fava beans), soybeans, salt, and red chili peppers. It’s the secret behind many iconic dishes like Mapo Tofu, Twice-Cooked Pork, and Sichuan Hot Pot, providing an umami-packed, complex flavor profile.
Fermenting your own Doubanjiang at home is a labor of love, requiring time and patience. But the results—a deeply flavorful, spicy, and savory paste—are well worth the effort. Here’s how you can ferment Doubanjiang at home.
Ingredients for Fermenting Doubanjiang
- Dried broad beans (fava beans): 500g (1.1 lbs)
- Soybeans: 200g (7 oz)
- Fresh red chili peppers: 300g (10.5 oz), chopped
- Salt: 250g (8.8 oz)
- Wheat flour: 100g (3.5 oz)
- Water: As needed
- Optional flavor enhancers: Ginger, garlic, Sichuan peppercorns (to taste)
Equipment
- Large bowl for soaking the beans
- Steamer or pot for cooking the beans
- Fermentation jar or crock (non-metallic)
- Cheesecloth or breathable cover
- Weights (to keep the beans submerged during fermentation)
Step-by-Step Guide to Fermenting Doubanjiang
1. Soak the Broad Beans and Soybeans
Begin by preparing the beans, which are the base of the paste.
- Soak the dried broad beans and soybeans in water for 24 hours. This will rehydrate the beans and make them easier to cook. After soaking, drain the beans.
2. Cook the Beans
After soaking, the beans need to be cooked until tender.
- Steam the soaked broad beans and soybeans for about 1-1.5 hours, or until they are soft but not falling apart. You can also boil them if steaming isn’t an option.
- Drain the beans and spread them out on a clean surface to cool.
3. Inoculate with Mold (Koji)
Koji mold is traditionally used in fermenting doubanjiang to kickstart the process. This step may seem complex, but it's essential for proper fermentation.
- After the beans have cooled, sprinkle them with wheat flour and mix thoroughly. The flour helps provide food for the koji mold during fermentation.
- Transfer the beans to a fermentation container and cover with a cheesecloth. Store them in a warm, humid area (around 25-30°C or 77-86°F) for 3-4 days to allow natural mold growth. This step creates the base for your fermentation.
4. Mash the Beans and Add Chili Peppers
Once the mold has started to grow on the beans, it’s time to create the paste.
- Transfer the molded beans into a large bowl and mash them coarsely. You can use a mortar and pestle or a food processor, but avoid making a smooth paste—leave some texture.
- Add the chopped chili peppers and salt to the mashed beans. The salt will help prevent unwanted bacterial growth and enhance the fermentation.
5. Ferment the Doubanjiang
This is where the magic happens. Doubanjiang requires a lengthy fermentation process to develop its rich, complex flavors.
- Transfer the mashed bean and chili mixture into a clean fermentation jar or crock.
- Place a weight on top of the mixture to keep it submerged under its own liquid. This prevents exposure to air and unwanted mold growth.
- Cover the jar with a breathable cloth or cheesecloth to allow gas to escape during fermentation.
- Leave the mixture in a cool, shaded place (away from direct sunlight) to ferment for at least 3 months, but up to 1 year. Stir the paste occasionally to check for any unwanted mold, and skim off any surface growth if necessary.
6. Monitor the Flavor Development
Over time, the Doubanjiang will darken in color and develop a deep, complex umami flavor. The longer you ferment it, the more intense the flavor becomes. Taste the paste periodically to decide when it reaches the desired balance of spice, saltiness, and richness.
7. Store and Use
Once the fermentation period is over, your Doubanjiang is ready to use.
- Transfer the fermented paste into clean jars with airtight lids. It can be stored in the refrigerator for up to a year, but the flavors will continue to develop even in cold storage.
- Use your homemade Doubanjiang in stir-fries, marinades, soups, and traditional Sichuan dishes like Mapo Tofu or Twice-Cooked Pork.
Why Ferment Your Own Doubanjiang?
While store-bought Doubanjiang is readily available, making your own gives you control over the ingredients and flavor profile. By fermenting it yourself, you can adjust the spice level, salt content, and fermentation time to suit your personal preferences. Plus, homemade Doubanjiang brings a depth of flavor that’s hard to find in commercial products, making your dishes taste more authentic and complex.
Conclusion
Fermenting Doubanjiang is a rewarding process that connects you with the heart of Sichuan cuisine. Though it requires time and patience, the end result is a flavor-packed paste that adds complexity, spice, and umami to a wide range of dishes. Whether you’re an avid fan of Sichuan cooking or just looking to try a new fermentation project, Doubanjiang is a must-try for food enthusiasts.