Cicerone Certified Beer Server Practice Exam

Oxygen is known to have a detrimental effect on beer flavor and aroma. When beer is exposed to oxygen, it can undergo oxidation, leading to off-flavors and aromas that are undesirable. This can manifest as cardboard-like or sherry-like notes, which are most evident in heavily hopped or more delicate styles of beer. Oxygen can also contribute to the degradation of certain hop compounds, stripping away the fresh and vibrant qualities that are key to many beer styles.

In contrast, carbon dioxide and nitrogen are gases commonly used in beer, primarily for carbonation and filling purposes. Carbon dioxide is essential for creating the bubbles in beer and contributes to its mouthfeel, without negatively impacting flavor when handled correctly. Nitrogen, often used in certain styles like stouts, leads to a creamier texture and smoother mouthfeel. Hydrogen is generally irrelevant in terms of beer flavor since it does not have a significant impact on the sensory characteristics of beer.

Understanding the role of oxygen in beer stability and quality is crucial for anyone involved in the brewing or serving of beer, as it highlights the importance of proper storage and handling to preserve the intended flavor profiles.