The metabolic behaviour of Halomonas variabilis (HV) during the production of extracellular polymeric substances (EPS) in a bio-reaction calorimeter (BioRC) was analysed. From the batch mode experiment pH, turbidity, oxygen supplied, carbon dioxide emitted and heat evolved were monitored and measured online through in-built sensors. EPS produced, substrate (glucose) consumed and biomass produced was measured every four hours of the reaction. The reaction was carried out in optimized conditions and the EPS yield achieved was 4.74 g/L in 12.5 h. The Best carbon source for EPS production from HV was glucose when compared to fructose, sucrose and maltose. The specific growth rate was found to be 0.156 h−1. A relationship between the metabolic heat and the growth rate of HV during EPS production in BioRC was developed.