To make Fermented Black Beans, cooked black soybeans are fermented in the water they were cooked in, then drained and mixed with salt, garlic and spices and allowed to dry in the sun.
The flavouring can vary by brand. Some can smell almost smoky, some more cheesy. Some Fermented Black Beans can taste more salty than others.
Fermented Black Beans will stick together somewhat. The less wrinkled they are, the fresher they are. Each bean will be about 1/2 inch (1 cm) long, and be firm but soft to the tongue.
They can also be made with a lighter-coloured variety of soybean, with darkening occurring during the fermentation process.
Fermented Black Beans are meant to be a condiment you buy, rather than make at home. They’re definitely not the kind of beans you’re meant to eat with a spoon right out of the tin by the campfire.
They are sold in cans, plastic bags or boxes (they’ll be inside a plastic bag that is then put in a box.) The box will actually be shaped like a can, except made of cardboard.
Fermented Black Beans are only used in Chinese cooking, not in other Asian cuisines.
A well-known brand is “Yang Jiang Preserved Beans”, which has ginger added.
Fermented Black Beans is not the same thing as black bean sauce, which is however made from Fermented Black Beans.
Some say that Fermented Black Beans should be soaked for half an hour first, then rinsed to remove excess salt and flavour. But whether to do this or not can depend on the brand, your taste and what you are using them for.
Depending on the recipe, Fermented Black Beans might be sprinkled over food before cooking, or mashed and used as a wet rub on meat or seafood, used in a sauce, or added to hot oil in a wok just before stir-frying (to flavour the oil).
Usually the beans are chopped or mashed first.
Fermented Black Beans are meant to be used in small quantities as a flavouring, perhaps a tablespoonful per recipe.
Fermented Black Beans are not regular black beans. Think of regular black beans as something you eat as a serving — versus Fermented Black Beans as a flavouring item, strong enough that 1 tablespoon per recipe is usually more than enough.
Try cooked soy beans and soy sauce, or Black Bean Sauce.
Once opened, you can store Fermented Black Beans in a sealed container in the fridge for up to 1 year. If they look dry, put a few drops of a neutral-flavoured oil on them. Making sure the container is tightly sealed will both help the beans from drying out, and help keep their smell contained.
Some people who buy Fermented Black Beans in the cardboard containers don’t even bother refrigerating them, they just fold the plastic inside back up (some people like to double bag this inside bit, to help contain the odour.)