Abstract:This study utilized barley malt and wheat malt as raw materials to brew German-style wheat beer using Munich classic,SafAleW-68 dry yeast,and the space-mutated yeast 303 carried aboard the ′Shenzhou-9′spacecraft.The objective was to compare the fermentation performance of these three yeasts and their influence on the physicochemical indicators of the beer,alongside conducting sensory evaluations.The results indicated that Munich classic and SafAleW-68 exhibited similar performance in terms of sugar reduction and alcohol production.However,SafAleW-68 demonstrated superior diacetyl reduction capability,significantly reducing its content.Although the space-mutated yeast 303 showed a slower initial fermentation rate,the process remained stable,ultimately achieving an alcohol content of 5.08% vol.Regarding physicochemical properties,beer brewed with SafAleW-68 displayed higher color intensity and turbidity,contributing to a distinctive appearance.In contrast,beer fermented with the space-mutated yeast 303 exhibited stronger bitterness,a higher pH,and a more robust flavor profile.Sensory evaluation results revealed that beer produced with the space-mutated yeast 303 received high scores in appearance,foam,aroma,and taste,characterized by fine foam,a notable ester aroma,and a well-balanced,unique flavor.