Cicerone Certified Beer Server Practice Test

What does the "International Bitterness Units" (IBU) scale measure?

1. The sweetness of beer

2. The bitterness of beer from hops

3. The alcohol content of beer

4. The carbon dioxide in beer

The correct answer is: The bitterness of beer from hops

The International Bitterness Units (IBU) scale is specifically designed to quantify the bitterness of beer, which primarily comes from hops. Hops are a key ingredient in brewing that contribute both flavor and aroma, but they are particularly known for imparting bitterness. The IBU scale measures the concentration of bitterness in a beer, and a higher IBU value indicates a more bitter taste. For example, a light lager may have an IBU of around 10, making it quite mild, while an imperial IPA could have an IBU exceeding 70, providing a robust bitterness that prominently affects the overall flavor profile. This scale is essential for brewers and consumers alike as it helps in understanding and comparing the levels of bitterness across different beer styles. The other options focus on different aspects of beer. Sweetness is not measured by IBU but rather by residual sugars, while alcohol content is assessed using the Alcohol by Volume (ABV) scale. Carbon dioxide levels are not directly measured in IBUs; instead, carbonation is typically evaluated through mouthfeel and perceived effervescence, not in bitterness terms.