This dataset compiles raw data on the physicochemical properties, enzyme activities, mould growth, and SEM of barley koji produced using Aspergillus oryzae and Aspergillus luchuensis under varying solid-state fermentation (SSF) conditions. Barley was inoculated and fermented at 30 °C and 35 °C for 42 hours. Samples were collected at 0, 12, 24, 28, 32, and 42 hours of fermentation. For more information, please contact the authors.