A method for producing the preparation containing protocatechuic acid (PCA), chlorogenic acid (CGA) and caffeic acid (CA) having a high concentration from coffee cascara comprising: (i) preparing materials; (ii) mixing the coffee cascara ingredient with the sweetener ingredient, and the water ingredient, and then sterilizing to obtain a foundation mixture; (iii) admixing the composition of complex enzyme-probiotic with the foundation mixture, then hydrolyzing to obtain a hydrolyzed mixture; (iv) admixing the composition of complex enzyme-probiotic with the hydrolyzed mixture, then fermenting to obtain a fermented mixture; (v) filtering the fermented mixture for removing the solid part, and collecting the liquid part is a fermented solution; and (vi) concentrating the fermented solution to obtain a preparation containing PCA, CGA and CA having a high concentration from coffee cascara.
