Fermented locust beans is a common traditional condiment in Nigeria, and other West African countries. We call it “iru” in Yoruba land, it is called “dawa dawa” in Hausa, and “ogiri okpe” in Igbo. It is also known as “sumbala”, “netetou”, and “kainda” in some parts of Africa. Most traditional stews, sauces and soups will not be complete without this pungent condiment.
Locust beans are seeds obtained from the pods of the African locust tree; Parkia biglobosa, which belongs to the family Mimosaceae. African locust bean is sometimes called carob because of the similarities in appearance, but they are different from each other. Carob comes from Ceratonia siliqua tree, which is typically found in the Mediterranean. It is also called Mediterranean locust beans, which explains the confusion between the two.
Mediterranean and African locust beans are used differently. Mediterranean locust beans pods are dried and processed into carob powder which could be used as an alternative to cocoa powder. Carob bean gum is also used to make thickeners and stabilizers for the Food Industry. Most of the parts of the African locust beans are utilised as food in some form or the other in West Africa, with the most prominent being the seeds. These are fermented into the condiment, iru (dawa dawa). The yellow pulp contained in the pod is very sweet and is also eaten.
HOW IS FERMENTED LOCUST BEANS (IRU) USED
Iru (dawa dawa) is used to flavours stews, sauces and other dishes like rice, native salads etc. It was one of the main condiments used in West Africa before bouillon cubes, and it is still a good alternative to bouillon cubes because of its nutritional and health benefits.
It has a pungent aroma which is not particularly attractive, but in a sauce or stew, the unmistakable umami flavour enhances the taste so much. A small amount of fermented locust beans in ila alasepo, ewedu, egusi soup or efo riro, and obe ata dindin lifts the taste in a delightful way.
In Yoruba land, there are two types of iru; “iru woro” and “iru pete”. The difference between the two is the addition of “kuuru”, an extract from zobo (Hibiscus sabdariffa) plant during the fermentation of iru pete. Iru pete has a mushy appearance while the seeds of iru woro are whole and have a bite to it when eaten.
It is important to wash fermented locust beans before use because there may be stone or sand residue from the traditional processing method.
HOW TO STORE FERMENTED LOCUST BEANS (IRU)
Fermentation not only helps to develop the flavor and aroma of iru (dawa dawa), it also helps to preserve it. This coupled with salting, and sometimes drying helps to maintain the shelf-life of the product without refrigeration in the tropical heat.
Fresh iru can be stored in the fridge for a few weeks and will keep for months the freezer. Dried Iru will keep in a cool and dry place for months. It should be stored in an air-tight container to stop the smell taking over the storage area.