One purpose of the present invention is to provide a processing technology that can increase the solubility of a processed hemp protein-including liquid composition while suppressing changes in flavor. Solubility has been increased while suppressing changes in flavor in this processed hemp protein-including liquid composition, which is obtained through a processed hemp protein-including liquid composition production method including a step in which a liquid composition that includes a hemp protein is treated with a bacteria-derived protease and a protein deamidating enzyme.