Okpei is what the Igbo version of the African miso tastes like — deeper, more pungent, more specifically southeastern Nigerian in character than iru. If you know the difference between Yoruba and Igbo soups, you know okpei. It's the Igbo signature in the pot.
More specifically Igbo than iru — Black American cooks with specific interest in southeastern Nigerian culinary tradition will want to distinguish this from Yoruba iru. Available through Nigerian-owned grocery stores in major metropolitan areas and through online African food retailers. The matrilineal transmission tradition makes okpei a specifically women's knowledge — the knowledge that Black women carried into diaspora.
Okpei's Bacillus subtilis fermentation produces fibrinolytic enzymes — nattokinase class — that dissolve fibrin clots and support cardiovascular health, confirmed in studies from the University of Nigeria, Nsukka that specifically analyzed Igbo fermented condiments. Antihypertensive peptides generated during fermentation are distinct from the iru profile — Igbo fermentation conditions produce slightly different peptide populations that show ACE-inhibitory activity at lower concentrations than some other locust bean ferments (Food Chemistry, 2018). Probiotic colonization of Bacillus subtilis natto strains supports gut barrier integrity. Free amino acid concentration is highest in okpei compared to iru and dawadawa in comparative analyses — providing immediate bioavailable protein without digestive work.
Used identically to iru — small amounts season entire pots. Igbo soups that specifically call for okpei: ofe akwu (palm nut soup), ofe oha (oha leaf soup), ofe onugbu (bitter leaf soup). The flavor is slightly more complex than iru — pairs especially well with native black soup and ukwa (African breadfruit) preparations. Available at Igbo-community-specific Nigerian grocery stores and online.
Free, no account needed to ask.