Cicerone Certified Beer Server Practice Exam

Using a hydrometer in brewing primarily serves the purpose of checking the alcohol content of the final product. A hydrometer measures the specific gravity of a liquid, which is the ratio of the density of the liquid to the density of water. Brewers take an initial specific gravity reading before fermentation begins and then take a final reading once fermentation is complete.

By comparing these two measurements, brewers can calculate the alcohol by volume (ABV). The difference in specific gravity indicates how much sugar has been converted into alcohol during fermentation. This is essential for brewers to understand the strength of their beer and to maintain consistency in their recipes.

Other aspects of brewing, such as measuring temperature or determining pH, require different tools and methods. While fermentation activity can involve observing the action of yeast, it is not directly measured by a hydrometer, making it a less suitable answer to the question. Thus, the primary purpose of a hydrometer is indeed to check the alcohol content, which aligns with option B.