Industrial practice in the brewing industry distinguishes specific - industrially useful phenotypes of brewing yeasts. Economically significant features characterizing these strains are aroma production, low temperature tolerance or the use of carbohydrates available in wort. These features in yeast are closely related to the genotype and its ploidity.which opens wide possibilities to changewith hybridization techniques. In addition, the heterosis phenomenon enables the enhancement of certain features in resulting hybrids.