The present invention relates to a method for the manufacture of a food material containing high quantities of cysteine. In this method, a yeast extract is prepared from yeast cells that contains .gamma.-glutamylcysteine and the extract is concentrated by controlling the temperature to be not greater than 60.degree. C. to prepare a food material in a liquid form, wherein the concentration of solids is at least 10% and the resulting food material is maintained at 70 to 130.degree. C.