The present invention relates to a cysteine synthase gene and use thereof, especially a brewery yeast having controlled hydrogen sulfide-producing capability, a process for producing alcoholic beverages with controlled hydrogen sulfide amount. More particularly, the present invention relates to a yeast whose hydrogen sulfide-producing capability that increases the product flavor is controlled by enhancing the expression level of YGR012W gene encoding brewery yeast cysteine synthase Ygr012wp, particularly non-ScYGR012W gene specific to lager brewing yeast, and to a method for producing alcoholic beverages with said yeast.