Abstract: The invention is concerned with the use of sorbitol to stabilize aqueous solutions of yeast lactases. The sorbitol is conveniently used in high concentration so as to act not only as a stabilizing agent but also as an antimicrobial agent. If desired, an antimicrobial agent other than sorbitol can be incorporated. Both aqueous solutions of yeast lactases containing sorbitol and processes for stabilizing aqueous solutions of yeast lactases by incorporation of sorbitol are claimed.