Ogiri is a pungent, savory fermented seed paste used in small amounts to season soups in southern Nigeria – in Igbo cooking especially – and elsewhere in West Africa. Cooked seeds are mashed, wrapped in leaves and left somewhere warm for a few days until they turn soft, dark and strongly aromatic. Different seeds give different ogiri:
- Ogiri isi – from castor seeds (Ricinus communis) (Aniche et al., 1993).
- Melon-seed ogiri – from egusi-type melon seeds (Nwosu & Ojimelukwe, 1993; Ogunsanwo et al., 1989).
- Sesame ogiri – made in Sierra Leone (Jonsyn, 1990).
It belongs to the same family of alkaline, Bacillus-fermented seasonings as dawadawa (iru), made from locust beans, and – further afield – Japanese natto.
What Ferments It
Bacillus bacteria do the work. In traditional castor-seed ogiri, the temperature of the fermenting mass rose from 28 to 42°C, and seeds inoculated with Bacillus, or Bacillus with Micrococcus, produced the typical ogiri odour (Aniche et al., 1993). Following ogiri and iru production in Nigeria, researchers found Bacillus species dominating – in ogiri, one group mostly related to B. safensis throughout – but also presumptive food-borne pathogens at some processing stages, which they put down to poor hygiene (Ademola et al., 2018). As the seed proteins break down, the paste becomes alkaline: in melon-seed ogiri the pH rose from 6.2 to 7.2 (Ogunsanwo et al., 1989). Igbo ugba, made from African oil beans, is another alkaline ferment.
Castor-Seed Ogiri: Buy It, Don’t Make It
Castor seeds contain ricin, a potent poison; chewing and swallowing them can cause serious injury (CDC). Ogiri isi is made by experienced producers who know how to process the seeds, but there’s no tested home method that shows how much ricin remains, and seeds sold as ornamentals or for oil aren’t a safe starting point. So this page gives no castor-seed recipe: buy ogiri isi from established West African producers and shops, or make melon-seed ogiri, which needs no detoxifying.
Mould and Mycotoxins
Oil seeds can carry aflatoxin-producing moulds. In a lab test, fermentation degraded aflatoxin added via contaminated melon seeds – by about two-thirds of aflatoxin B1 after three days and fully by the fourth – and no aflatoxin was found in 26 market samples (Ogunsanwo et al., 1989). But in Sierra Leone, toxigenic Aspergillus and Penicillium appeared in sesame ogiri when it was handled poorly (Jonsyn, 1990). Start with clean, sound seeds, keep everything clean, and discard any batch with green, yellow or black mould.
Using Ogiri
A little goes a long way: a piece the size of a hazelnut seasons a pot of soup. It’s stirred into egusi, ofe onugbu (bitter leaf) and oha soups and simmered, where its smell mellows into a deep savoriness – much as fish sauce or shrimp paste work in Southeast Asian cooking. Use it cooked.