Cicerone Certified Beer Server Practice Exam

What type of beer fermentation occurs at warmer temperatures and typically produces more fruity esters?

1. Aerobic fermentation

2. Bottom fermentation

3. Top fermentation

4. Secondary fermentation

The correct answer is: Top fermentation

The correct answer is top fermentation. This process is characterized by the use of ale yeast, specifically Saccharomyces cerevisiae, which operates best at warmer fermentation temperatures, generally between 60°F to 75°F (15°C to 24°C). These higher temperatures promote a more vigorous fermentation, leading to the production of various compounds, including fruity esters and phenols. These esters are responsible for the wide range of fruity flavors often found in ales, making top fermentation key to producing many of the styles that craft brewers are known for. In contrast, other types of fermentation like bottom fermentation are conducted at cooler temperatures, leading to a cleaner and crisper taste with fewer fruity esters, which is often seen in lagers. Aerobic fermentation typically involves yeast activity with oxygen present, which is more relevant to the production of certain types of sour beers rather than the esters created in ales. Secondary fermentation refers to a later stage in beer production where fermentation can lead to further conditioning or clarification, but does not specifically relate to the temperature effects and ester production of the initial fermentation process.