Takjoo mashes which were collected from the Takjoo breweries in Seoul area were studied on the purpose of detection for the reciprocal actions between amylase activity and saccharifying ability. The results obtained are as follows. Amylase activity was found to be usually high in the primary brewing process as well as the main brewing process. And especially, .alpha.-amylase in the primary brewing process showed remarkably high activity, more than 5.0 D.P. per/ml of mash comparing with 3.8 D.P. per ml of mash in the main brewing process. However, it was revealed that the reducing sugar contents in the primary brewing process were much higher in its average contents, 5.5%, than 1.1% in the main brewing process.