Background: Celebrity endorsement in marketing has significantly grown in the past 30 years, earning their vital position in brand communication strategies. Recognizing that celebrities can shape consumer behavior, especially among younger generations like Gen Z, marketers extensively allocate a substantial proportion of their budget to celebrity endorsers. As beverage marketing is a high-budget marketing field, it is frequently endorsed by celebrities. Within the beverage market, beer is the leading beverage in the global alcohol consumption rankings in terms of volume. Since beer has been a distinct element within German history and culture, it continuously generates billions of dollars per year for the German market and is hence of high importance for the marketing field.

Purpose: Celebrities are crucial for brands that aim to boost their symbolic values to enhance brand credibility or appeal, and the beverage industry is frequently employing this marketing tactic. Hence, the aim of this research to investigate the perception of credibility in celebrity endorsements within beverage marketing. Observing German Gen Z, who are prone to consume beer while being accompanied by an adult as early as the age of 14 within Germany, the age group is of key importance to research due to their responsiveness to celebrity endorsements and influence over consumer culture. Therefore, the main research purpose is to examine how the credibility of endorsing celebrities affects German Gen Z (born between 1995 and 2010), and to identify the associated positive and negative effects on their purchase intentions specifically for alcoholic and non-alcoholic beer.

Method: The thesis being of a conclusive and causal nature, a quantitative research design was applied. Precisely, a between-subjects experiment was conducted. The empirical data was collected within two weeks, utilizing an experiment and randomizing two different conditions within the experiment. One condition presents an alcoholic beer commercial and the other presents a non-alcoholic beer commercial. Finally, 289 respondents participated in the study whose answers were evaluated. By using a deductive approach, the data was analyzed with SPSS and SPSS Process and compared to the previously provided theoretical framework.

Conclusion: Expertise as one dimension of credibility is of proven importance in beverage marketing when creating commercials with celebrities and has displayed an evident effect on purchase intention. Furthermore, it was identified that within the non-alcoholic commercials conditions, both genders rated lower in their purchase intention, however, this outcome of difference with gender could not be explained by the perceived expertise and hence other elements such as bias need to be considered. Moreover, the research showed that customers' purchase intentions are positively influenced by strong congruence between the celebrity and the endorsed brand or product.