Abstract: Traditionally prepared cereal based complementary food are too dilute for adequate energy and nutrient density as infant complementary food. The consistency of complementary food is of particular importance for infants who cannot masticate and therefore, depend on liquid or semi solid foods. In Nigeria mothers regard cereal malting and supplementation with legume as extra-labor. Increase of gruel energy density is important to improve the energy intake of young children in developing countries. This study investigated the effect of malting and co-fermentation bi-component flour (co-fermented maize/cowpea70:30w/w) on the consistency of the gruel product. Five processes in which either of the grain is germinated, un-germinated, un-germinated and boiled, un-germinated boiled, wet-milled and sieved before co-fermentation were explored. Consistency of the gruel of the products with concentration ranging from 4-18%; was measured using Bostwick Consistometer. The dry matter of the gruel was determined according to standard method. It was observed that boiling and milling of un-germinated maize and cowpea before co-fermentation was more effective in viscosity reduction at 12% flour concentration. At 12% flour concentration that boiling and milling of un-germinated maize and cowpea before co-fermentation can enhance the consistency and by implication reduce the viscosity of co-fermented maize/cowpea as infant complementary food.