Is all brewing yeast the same?
As a sommelier and brewer, I can confidently say that not all brewing yeast is the same. While there are many different strains of yeast used in brewing, the two most common types are ale yeast and lager yeast. These two yeasts have distinct characteristics that contribute to the flavors and aromas of the final beer.
1. Ale yeast:
Ale yeast is a top-fermenting yeast that is typically used to brew ales, which are known for their complex flavors and fruity esters. This yeast ferments at warmer temperatures (around 60-75°F or 15-24°C) and works relatively quickly, usually finishing fermentation within a few days to a week. It produces a range of flavors, including fruity, spicy, and sometimes even earthy notes, depending on the specific strain used.
Personal experience: I remember brewing my first ale using a popular English ale yeast strain. The fermentation process was lively, with the yeast creating a thick krausen on top of the beer. The resulting ale had a wonderful fruity aroma with hints of pear and a slightly spicy finish.
2. Lager yeast:
Lager yeast, on the other hand, is a bottom-fermenting yeast that is typically used to brew lagers. Lagers are known for their clean, crisp flavors and smooth finish. Unlike ale yeast, lager yeast ferments at much cooler temperatures (around 45-55°F or 7-13°C) and requires a longer fermentation period, often several weeks or even months. This slow fermentation process allows for the development of subtle flavors and a well-rounded character.
Personal experience: I once brewed a Czech Pilsner using a traditional lager yeast strain. The fermentation process was much slower compared to ale yeast, requiring a period of cold conditioning to allow the flavors to develop fully. The resulting Pilsner had a clean, malty taste with a hint of floral hop aroma and a smooth, refreshing finish.
It's important to note that within the categories of ale and lager yeast, there are numerous strains available, each with its own unique characteristics. Some strains may produce more fruity esters, while others may emphasize spicy or floral notes. Brewers often experiment with different yeast strains to create specific beer styles or to add complexity to their recipes.
In addition to ale and lager yeast, there are other specialized yeast strains used in brewing, such as wheat yeast for brewing wheat beers or Belgian yeast for brewing Belgian-style ales. These strains contribute their own distinct flavors and aromas to the final product.
While all brewing yeast serves the same purpose of fermenting sugars into alcohol, the specific strain of yeast used greatly impacts the flavor profile and characteristics of the beer. Ale yeast and lager yeast, in particular, have their own unique attributes that make them suitable for different beer styles. The choice of yeast is an essential decision for brewers, as it can greatly influence the final result and contribute to the artistry of brewing.