Rice bran contains high protein and is potential to be used as a substitute for wheat flour in making cookies. Until now
wheat flour is still imported so that the development of rice bran through fermentation biotechnology is able to increase
protein content and improve digestibility. This study examined the effects of tape yeast and tempeh yeast at concentrations
of 1%, 2% and 3% and fermentation times of 15, 28, and 41 h, so that there were 18 experimental units. The best results
were obtained with the use of 2% tape yeast for 41 h. Further studies on optimization of the fermentation process gave
optimum results in the fermentation process of 2.10% yeast for 42 h and 30 minutes. Under these conditions, rice bran flour
can be produced with a protein content of 18.5%. Furthermore, for the application of fermented rice bran flour as a substitute
for wheat flour in cookies making, the best results were obtained at the ratio of 20% rice bran flour and 80% wheat flour
based on the taste and aroma of the cookies product. Substitution of wheat flour with rice bran flour is only organoleptically
feasible at a maximum level of 30%.