Tannase is an enzyme used in various industries and produced by a large number of microorganisms. The aim of this study was to evaluate tannase production to determine the biochemical, kinetic, and thermodynamic properties and to simulate tannase in vitro digestion. The tannase-producing fungal strain was isolated from jamun leaves and identified as Aspergillus tamarii. Temperature at 26 degrees C for 67h was the best combination for maximum tannase activity (6.35-fold; initial activity in Plackett-Burman design15.53U/mL and average final activity in Doehlert design-98.68U/mL). The crude extract of tannase was optimally active at 40 degrees C, pH 5.5 and 6.5. Moreover, tannase was stimulated by Na+, Ca2+, Mg2+, and Mn2+. The half-life at 40 degrees C lasted 247.55min. The free energy of Gibbs, enthalpy, and entropy, at 40 degrees C, was 81.47, 16.85, and -0.21kJ/molK, respectively. After total digestion, 123.95% of the original activity was retained. Results suggested that tannase from A. tamarii URM 7115 is an enzyme of interest for industrial applications, such as gallic acid production, additive for feed industry, and for beverage manufacturing, due to its catalytic and thermodynamic properties.