The objective of this research was to study the following fermentation variables in a batch bioreactor of (a) ethanol concentration of 4, 6, and 8 percent by weight per volume, (b) inoculum concentration of 5, 7.5, 10 and 15 percent, (c) aeration rate of 0.47, and 0.76 volume of airflow rate per minute per volume of substrate, (d) agitation rate of 200, 250, 300 rotations per minute, and (e) fermentation time in order to produce the acetic acid product concentration, Cp and microbial growth of Acetobacter aceti (A.aceti) concentration, Cx and also to study how to simulate the values of C(p) and C(x) derived from a mathematical modelling that is to compare the values of C(p) and C(x) from the experiment data and simulation results. The benefit of this research is to convert from the research results at a laboratory scale to successful commercial size design. The method used in this research can be divided into three stages, namely; determination of kinetic parameters, simulation model, and validation of the results. The research results can be shown that ethanol concentration of 6 percent by weight per volume, agitation rate of 300 rotations per minute, inoculum concentration of 7.5 percent by volume, aeration rate between of 0.4 7, to 0.76 volume of air flow rule per minute per volume of substrate of ethanol in order to get acetic acid concentration, C(p) and microbial cell of A.aceti concentration,C(x) and the profile of C(p), and C(x) from simulation model is the some as the profile of C(p) and C(x) from the experiment data.