What makes a beer a lager?

Answered by Bill Hernandez

When it comes to , there are two main categories: ales and lagers. While both are delicious and enjoyable in their own right, they differ in several key aspects. In this detailed answer, I will explore what makes a beer a and delve into the unique characteristics that set it apart from ales.

1. Fermentation Process:
The primary factor that distinguishes a lager from an is the fermentation process. Lagers are brewed using bottom-fermenting yeasts, scientifically known as Saccharomyces pastorianus. These yeasts sink to the bottom of the fermentation tank during the process. In contrast, ales are brewed using top-fermenting yeasts, scientifically known as Saccharomyces cerevisiae, which rise to the top during fermentation. This fundamental difference in behavior contributes to the distinct qualities of lagers.

2. Temperature Control:
Another crucial aspect of brewing lagers is the temperature at which they are fermented. Lager yeasts thrive at lower temperatures compared to ale yeasts. The fermentation process for lagers typically occurs between 45 to 55 degrees Fahrenheit (7 to 13 degrees Celsius). This low-temperature environment results in a slower fermentation process, which allows the flavors to develop more gradually and subtly. On the other hand, ales ferment at higher temperatures, typically between 60 to 75 degrees Fahrenheit (15 to 24 degrees Celsius), resulting in a faster fermentation process with bolder and more pronounced flavors.

3. Maturation Period:
In addition to the fermentation process, lagers require a longer maturation period compared to ales. After primary fermentation, lagers undergo a secondary fermentation, known as lagering. During this stage, the beer is stored at near-freezing temperatures for several weeks or even months. This extended period allows the flavors to mellow and harmonize, resulting in a smooth and crisp taste. Ales, on the other hand, generally have a shorter maturation period and are often consumed at a younger age.

4. Flavor Profile:
The distinct characteristics of lagers can be attributed to their fermentation and maturation processes. Lagers are known for their clean, crisp, and refreshing taste. They typically exhibit a smooth mouthfeel, moderate to high carbonation, and a well-balanced flavor profile. Lagers tend to have a subtle and delicate presence, with a focus on showcasing the used. The fermentation at lower temperatures also contributes to the clean finish and minimal fruity or estery flavors commonly found in ales.

5. Lager Styles:
Lagers encompass a wide range of styles, each with its own unique attributes. Some popular lager styles include Pilsner, Helles, Bock, Märzen, and Dunkel. Each style has its own specific characteristics, ranging from light and refreshing to rich and malty. These diverse styles showcase the versatility of lagers and cater to a wide range of preferences.

What makes a beer a lager is primarily the use of bottom-fermenting yeasts, the lower fermentation temperatures, and the longer maturation period. These factors contribute to the clean, crisp, and well-balanced flavors that are characteristic of lagers. Whether you're enjoying a refreshing Pilsner on a hot summer day or savoring a rich and malty Bock during the colder months, lagers offer a diverse and enjoyable beer-drinking experience.