Thermodynamic properties and mold appearance analysis of major corn stover components such as leaf, stalk skin, and stalk pith were determined from the sorption isotherms data in the temperature range of 10°C to 40°C. Brunauer-Emmet-Teller (BET) monolayer moistures decreased with an increase in temperature. Net isosteric heat of sorption and differential entropy values reduced exponentially with moisture increase and approached the latent heat of vaporization of pure water. Leaf had the highest spreading pressure followed by stalk skin and stalk pith. Spreading pressures increased with increase in water activity and reduced with temperature increase. Net integral enthalpy increased with moisture content to a maximum and decreased afterwards, whereas net integral entropy displayed a reverse trend. Mean values of net integral enthalpy and entropy of stalk pith was the maximum followed by leaf and stalk skin. Thermodynamic properties of corn stover find application in moisture-material interaction, sorption and desorption kinetics, and energy calculations that in turn lead to the development of efficient processing and handling systems. Spoilage status of samples of isotherm experiment was assessed by visual observation of mold growth. Mold affected all stover components at water activity > 0.90. High temperatures were conducive for mold growth and stalk pith was the least resistant to mold growth followed by stalk skin and leaf. Mold free days were predicted using a new three-parameter (temperature (T), water activity (a w ), and T × a w ) model (R 2 = 0.99), with results comparable with existing exponential model (R 2 = 0.95). The advantage of the developed model was to predict the safe storage period of corn stover from the storage environmental conditions.