Sixteen commercial samples of ogi, obtained by using traditional "Goun" methodology, from Cotonou and the surrounding area were characterized and compared with maize raw material. Goun methodology uses floury/friable grains and gives a high yield (84%, db) of a very white (L* value close to 83) and fine (median particle size about 40 um) slurry. The yield of Beninese ogi, its final water content (58%) and acidity after 3 days of fermentation were slightly higher than for ogi produced using the Nigerian or Ghanaian technology. About 40% of total proteins were lost during the manufacture of ogi, but the digestibility of the residual proteins increased by 20%. At least 50% of both macro- and micromineral elements were lost, with the exception of Fe and Na, whose contents increased. Pasting properties of Beninese ogis were similar to that of mawè, another fermented slurry from Benin. The dominant microflora involved in Beninese ogi was a mixed population of lactic acid bacteria and yeasts, mainly lactobacilli and Candida. The difference in microflora composition compared with Nigerian ogi is probably due to the specific trot grain sleeping procedure of the Beninese 'Goun' methodology.