You might think you know what fermented black beans are, especially if you eat a lot of Mexican food, but you might be surprised. These are not the black beans you'll find in Mexican cooking. Fermented black beans, which are also called salted or dried black beans, are made from soybeans that have been dried and fermented with salt; other ingredients such as chiles, wine, and ginger might be added.
Because of their very salty and slightly bitter flavor, fermented black beans are frequently paired with other strong seasonings, such as garlic and chile peppers. They are normally rinsed before being used in cooking because otherwise, they will make a dish taste too salty. For best results, rehydrate the black beans in water or another liquid called for in the recipe, such as rice wine, vinegar, or soy sauce. Soaking for just a few minutes will plump them up enough for cooking. They can be added in several different stages: at the beginning of cooking, during cooking, or at the very end, depending on the flavor experience you're going for. At the beginning, they lend an umami note; toward the end, it's more of a funky flavor and texture experience, since they haven't had time to cook down.
Fermented black beans make a frequent appearance in Cantonese cooking, where you’ll find them in dishes such as shrimp with lobster sauce and as a key component in lobster Cantonese. You’ll often find recipes calling for the beans to be mashed with garlic and/or ginger, and then rubbed over the meat prior to cooking, or added at the beginning of a stir-fry. Sometimes it is poured over steamed dishes along with other liquid ingredients.
Where to Buy Fermented Black Beans
Fermented black beans are sold in plastic bags in Asian markets. Remove the beans from the package and store them in a sealed container in a cool, dark place. The beans will last for several months. You can also find fermented black beans sold in jars. These can be used instead if necessary, but they don't have as much flavor.
If you don’t live near an Asian market, premade black bean sauce is often available in the international section of many supermarkets. You can also buy both fermented black beans and premade black bean sauce at several online stores specializing in Asian ingredients. Lee Kum Kee is a good brand to look for. You can use black bean sauce in pinch as a substitute, but it's not quite the same thing as fermented black beans.
Fermented black beans are also called Chinese black beans, dried black beans, salted black beans, douchi, and tausi.