A method for identifying barley with good brewing properties using the thermostability of the barley beta-amylase as an indicator. The thermostability of the barley beta-amylase significantly affects the degree of the apparent attenuation limit. A method for determining the enzyme activity of a extract solution from one barley seed, an indirect method by an isoelectric point, and an indirect identifying method by DNA polymorphisms of the region containing the beta-amylase structural gene have been developed as a method for determining the type of thermostability for a barley beta-amylase. The selection method is not affected by environmental or climatic conditions.
